diff --git a/examples/cosmo_box_gravity_only_3d/Config.sh b/examples/cosmo_box_gravity_only_3d/Config.sh
new file mode 100755
index 0000000000000000000000000000000000000000..9e1c854fa77481daa25b30903ae4c2a1cf42d877
--- /dev/null
+++ b/examples/cosmo_box_gravity_only_3d/Config.sh
@@ -0,0 +1,54 @@
+#!/bin/bash        	# this line only there to enable syntax highlighting in this file
+
+##################################################
+#  Enable/Disable compile-time options as needed #
+#  examples/cosmo_box_gravity_only_3d/Config.sh  #
+##################################################
+
+
+#--------------------------------------- Gravity treatment
+SELFGRAVITY                              # gravitational intraction between simulation particles/cells  	 
+HIERARCHICAL_GRAVITY                     # use hierarchical splitting of the time integration of the gravity
+CELL_CENTER_GRAVITY                      # uses geometric centers to calculate gravity of cells, only possible with HIERARCHICAL_GRAVITY
+ALLOW_DIRECT_SUMMATION                   # Performed direct summation instead of tree-based gravity if number of active particles < DIRECT_SUMMATION_THRESHOLD (= 3000 unless specified differently here)
+DIRECT_SUMMATION_THRESHOLD=500           # Overrides maximum number of active particles for which direct summation is performed instead of tree based calculation
+
+#--------------------------------------- Gravity softening
+NSOFTTYPES=2                             # Number of different softening values to which particle types can be mapped.
+MULTIPLE_NODE_SOFTENING                  # If a tree node is to be used which is softened, this is done with the softenings of its different mass components
+INDIVIDUAL_GRAVITY_SOFTENING=32          # bitmask with particle types where the softenig type should be chosen with that of parttype 1 as a reference type
+ADAPTIVE_HYDRO_SOFTENING                 # Adaptive softening of gas cells depending on their size
+
+#--------------------------------------- TreePM Options
+PMGRID=256                               # Enables particle mesh; number of cells used for grid in each dimension
+RCUT=5.0                                 # This can be used to override the maximum radius in which the short-range tree-force is evaluated (in case the TreePM algorithm is used). The default value is 4.5, given in mesh-cells.
+
+#--------------------------------------- Time integration options
+TREE_BASED_TIMESTEPS                     # non-local timestep criterion (take 'signal speed' into account)
+
+#--------------------------------------- Single/Double Precision
+DOUBLEPRECISION=1                        # Mode of double precision: not defined: single; 1: full double precision 2: mixed, 3: mixed, fewer single precisions; unless short of memory, use 1.
+DOUBLEPRECISION_FFTW                     # FFTW calculation in double precision
+OUTPUT_COORDINATES_IN_DOUBLEPRECISION    # will always output coordinates in double precision
+NGB_TREE_DOUBLEPRECISION                 # if this is enabled, double precision is used for the neighbor node extension
+
+#--------------------------------------- On the fly FOF groupfinder
+FOF                                      # enable FoF output
+FOF_PRIMARY_LINK_TYPES=2                 # 2^type for the primary dark matter type
+FOF_SECONDARY_LINK_TYPES=1+16+32         # 2^type for the types linked to nearest primaries
+
+#--------------------------------------- Subfind
+SUBFIND                                  # enables substructure finder
+SAVE_HSML_IN_SNAPSHOT                    # stores hsml, density, and velocity dispersion values in the snapshot files
+SUBFIND_CALC_MORE                        # calculates also the velocity dispersion in the local density estimate (this is automatically enabled by several other options, e.g. SAVE_HSML_IN_SNAPSHOT)
+SUBFIND_EXTENDED_PROPERTIES              # adds calculation of further quantities related to angular momentum in different components
+
+#-------------------------------------------- Things for special behaviour
+PROCESS_TIMES_OF_OUTPUTLIST              # goes through times of output list prior to starting the simulaiton to ensure that outputs are written as close to the desired time as possible (as opposed to at next possible time if this flag is not active)
+
+#--------------------------------------- Output/Input options
+REDUCE_FLUSH                             # only flush output to log-files in predefined intervals
+HAVE_HDF5                                # needed when HDF5 I/O support is desired (recommended)
+
+#--------------------------------------- Testing and Debugging options
+DEBUG                                    # enables core-dumps
diff --git a/examples/cosmo_box_gravity_only_3d/L50n32/ics b/examples/cosmo_box_gravity_only_3d/L50n32/ics
new file mode 100644
index 0000000000000000000000000000000000000000..66dd0c6b3b0a617058bc6f692287d35f55075709
Binary files /dev/null and b/examples/cosmo_box_gravity_only_3d/L50n32/ics differ
diff --git a/examples/cosmo_box_gravity_only_3d/L50n32/inputspec_ics.txt b/examples/cosmo_box_gravity_only_3d/L50n32/inputspec_ics.txt
new file mode 100644
index 0000000000000000000000000000000000000000..20fef05848ee2ae60d4fce12d63c384ccab6d599
--- /dev/null
+++ b/examples/cosmo_box_gravity_only_3d/L50n32/inputspec_ics.txt
@@ -0,0 +1,561 @@
+         127      100.387
+ 6.28319e-06  0.000217757     6.28364e-06  0.000217764
+ 6.44026e-06   0.00023806     6.44078e-06  0.000238068
+ 6.60127e-06  0.000260194     6.60184e-06  0.000260204
+  6.7663e-06  0.000284317     6.76694e-06  0.000284329
+ 6.93546e-06  0.000310601     6.93618e-06  0.000310616
+ 7.10885e-06  0.000339229     7.10965e-06  0.000339247
+ 7.28657e-06  0.000370401     7.28747e-06  0.000370422
+ 7.46873e-06  0.000404332     7.46974e-06  0.000404356
+ 7.65545e-06  0.000441252     7.65658e-06  0.000441281
+ 7.84684e-06  0.000481411      7.8481e-06  0.000481446
+ 8.04301e-06  0.000525079     8.04442e-06  0.000525121
+ 8.24408e-06  0.000572543     8.24566e-06  0.000572593
+ 8.45019e-06  0.000624114     8.45194e-06  0.000624174
+ 8.66144e-06  0.000680127      8.6634e-06  0.000680198
+ 8.87798e-06  0.000740938     8.88017e-06  0.000741023
+ 9.09993e-06  0.000806932     9.10237e-06  0.000807033
+ 9.32742e-06   0.00087852     9.33015e-06   0.00087864
+ 9.56061e-06  0.000956142     9.56366e-06  0.000956284
+ 9.79962e-06   0.00104027     9.80302e-06   0.00104044
+ 1.00446e-05    0.0011314     1.00484e-05    0.0011316
+ 1.02957e-05   0.00123007        1.03e-05   0.00123031
+ 1.05531e-05   0.00133685     1.05578e-05   0.00133713
+  1.0817e-05   0.00145235     1.08222e-05   0.00145268
+ 1.10874e-05    0.0015772     1.10932e-05    0.0015776
+ 1.13646e-05   0.00171209      1.1371e-05   0.00171256
+ 1.16487e-05   0.00185774     1.16559e-05    0.0018583
+ 1.19399e-05   0.00201491     1.19479e-05   0.00201557
+ 1.22384e-05    0.0021844     1.22473e-05   0.00218517
+ 1.25443e-05   0.00236705     1.25542e-05   0.00236796
+  1.2858e-05   0.00256374     1.28689e-05   0.00256481
+ 1.31794e-05   0.00277539     1.31916e-05   0.00277665
+ 1.35089e-05   0.00300297     1.35224e-05   0.00300446
+ 1.38466e-05   0.00324748     1.38616e-05   0.00324923
+ 1.41928e-05   0.00350996     1.42094e-05   0.00351201
+ 1.45476e-05   0.00379148      1.4566e-05   0.00379389
+ 1.49113e-05   0.00409316     1.49316e-05   0.00409597
+ 1.52841e-05   0.00441613     1.53066e-05   0.00441942
+ 1.56662e-05   0.00476156      1.5691e-05   0.00476541
+ 1.60578e-05   0.00513064     1.60853e-05   0.00513514
+ 1.64593e-05   0.00552461     1.64896e-05   0.00552986
+ 1.68708e-05    0.0059447     1.69042e-05   0.00595081
+ 1.72925e-05   0.00639218     1.73293e-05   0.00639929
+ 1.77248e-05   0.00686834     1.77654e-05    0.0068766
+  1.8168e-05   0.00737448     1.82126e-05   0.00738407
+ 1.86222e-05   0.00791194     1.86712e-05   0.00792306
+ 1.90877e-05   0.00848208     1.91416e-05   0.00849495
+ 1.95649e-05   0.00908629     1.96241e-05   0.00910117
+  2.0054e-05   0.00972601     2.01189e-05   0.00974318
+ 2.05554e-05    0.0104027     2.06265e-05    0.0104225
+ 2.10693e-05     0.011118     2.11472e-05    0.0111408
+  2.1596e-05    0.0118734     2.16813e-05    0.0118996
+ 2.21359e-05    0.0126706     2.22292e-05    0.0127007
+ 2.26893e-05    0.0135116     2.27913e-05    0.0135461
+ 2.32565e-05    0.0143981     2.33679e-05    0.0144377
+ 2.38379e-05    0.0153323     2.39595e-05    0.0153776
+ 2.44339e-05    0.0163163     2.45665e-05    0.0163682
+ 2.50447e-05    0.0173526     2.51893e-05    0.0174119
+ 2.56708e-05    0.0184436     2.58283e-05    0.0185113
+ 2.63126e-05    0.0195921      2.6484e-05    0.0196694
+ 2.69704e-05     0.020801     2.71569e-05    0.0208891
+ 2.76447e-05    0.0220733     2.78475e-05    0.0221738
+ 2.83358e-05    0.0234124     2.85563e-05    0.0235269
+ 2.90442e-05    0.0248216     2.92838e-05    0.0249521
+ 2.97703e-05    0.0263047     3.00305e-05    0.0264532
+ 3.05146e-05    0.0278654     3.07971e-05    0.0280346
+ 3.12774e-05    0.0295077     3.15841e-05    0.0297003
+ 3.20594e-05    0.0312358      3.2392e-05    0.0314551
+ 3.28609e-05     0.033054     3.32217e-05    0.0333036
+ 3.36824e-05    0.0349667     3.40736e-05    0.0352509
+ 3.45244e-05    0.0369785     3.49485e-05    0.0373021
+ 3.53875e-05    0.0390942      3.5847e-05    0.0394625
+ 3.62722e-05    0.0413185       3.677e-05    0.0417378
+  3.7179e-05    0.0436565     3.77181e-05    0.0441337
+ 3.81085e-05    0.0461131     3.86922e-05    0.0466561
+ 3.90612e-05    0.0486936      3.9693e-05    0.0493113
+ 4.00378e-05     0.051403     4.07214e-05    0.0521055
+ 4.10387e-05    0.0542469     4.17783e-05    0.0550455
+ 4.20647e-05    0.0572305     4.28645e-05    0.0581378
+ 4.31163e-05    0.0603593     4.39811e-05    0.0613895
+ 4.41942e-05    0.0636389      4.5129e-05    0.0648077
+ 4.52991e-05     0.067075     4.63092e-05    0.0683997
+ 4.64315e-05    0.0706731     4.75227e-05    0.0721731
+ 4.75923e-05    0.0744389     4.87707e-05    0.0761354
+ 4.87821e-05    0.0783784     5.00543e-05    0.0802945
+ 5.00017e-05    0.0824972     5.13747e-05    0.0846586
+ 5.12517e-05    0.0868013      5.2733e-05    0.0892358
+  5.2533e-05    0.0912966     5.41306e-05    0.0940347
+ 5.38463e-05    0.0959889     5.55687e-05    0.0990638
+ 5.51925e-05     0.100884     5.70488e-05     0.104332
+ 5.65723e-05     0.105989     5.85722e-05     0.109849
+ 5.79866e-05     0.111308     6.01405e-05     0.115624
+ 5.94363e-05     0.116849     6.17551e-05     0.121666
+ 6.09222e-05     0.122616     6.34176e-05     0.127986
+ 6.24452e-05     0.128617     6.51298e-05     0.134595
+ 6.40064e-05     0.134857     6.68933e-05     0.141504
+ 6.56065e-05     0.141341     6.87098e-05     0.148724
+ 6.72467e-05     0.148077     7.05814e-05     0.156267
+ 6.89279e-05      0.15507     7.25099e-05     0.164147
+ 7.06511e-05     0.162326     7.44974e-05     0.172377
+ 7.24173e-05     0.169851     7.65459e-05      0.18097
+ 7.42278e-05      0.17765     7.86578e-05     0.189942
+ 7.60835e-05      0.18573     8.08352e-05     0.199309
+ 7.79855e-05     0.194096     8.30807e-05     0.209086
+ 7.99352e-05     0.202755     8.53966e-05     0.219293
+ 8.19336e-05      0.21171     8.77858e-05     0.229948
+ 8.39819e-05     0.220969     9.02508e-05     0.241069
+ 8.60815e-05     0.230537     9.27946e-05      0.25268
+ 8.82335e-05     0.240419     9.54203e-05     0.264801
+ 9.04393e-05      0.25062      9.8131e-05     0.277458
+ 9.27003e-05     0.261146      0.00010093     0.290675
+ 9.50178e-05     0.272002     0.000103821      0.30448
+ 9.73933e-05     0.283192     0.000106807     0.318902
+ 9.98281e-05     0.294723     0.000109893     0.333974
+ 0.000102324     0.306598     0.000113082     0.349729
+ 0.000104882     0.318823     0.000116378     0.366203
+ 0.000107504     0.331402     0.000119787     0.383436
+ 0.000110192      0.34434     0.000123313     0.401472
+ 0.000112946     0.357642     0.000126961     0.420355
+  0.00011577      0.37131     0.000130737     0.440138
+ 0.000118664     0.385351     0.000134645     0.460876
+ 0.000121631     0.399768     0.000138693     0.482628
+ 0.000124672     0.414565     0.000142886     0.505461
+ 0.000127788     0.429746     0.000147232     0.529448
+ 0.000130983     0.445315     0.000151738      0.55467
+ 0.000134258     0.461275     0.000156412     0.581215
+ 0.000137614      0.47763     0.000161262     0.609183
+ 0.000141054     0.494385     0.000166297     0.638684
+ 0.000144581     0.511541     0.000171528      0.66984
+ 0.000148195     0.529103     0.000176965     0.702789
+   0.0001519     0.547074      0.00018262     0.737688
+ 0.000155698     0.565457     0.000188506     0.774711
+  0.00015959     0.584255     0.000194636     0.814055
+  0.00016358     0.603471     0.000201026     0.855948
+ 0.000167669     0.623108     0.000207693     0.900645
+ 0.000171861     0.643169     0.000214655     0.948439
+ 0.000176158     0.663657     0.000221932     0.999666
+ 0.000180562     0.684574     0.000229549      1.05471
+ 0.000185076     0.705923     0.000237531      1.11402
+ 0.000189703     0.727707     0.000245905      1.17812
+ 0.000194445     0.749928     0.000254704      1.24758
+ 0.000199306      0.77259     0.000263964      1.32311
+ 0.000204289     0.795693     0.000273724       1.4055
+ 0.000209396     0.819242     0.000284031      1.49569
+ 0.000214631     0.843238     0.000294935      1.59477
+ 0.000219997     0.867683     0.000306492        1.704
+ 0.000225497     0.892581     0.000318767      1.82487
+ 0.000231134     0.917933     0.000331831       1.9591
+ 0.000236913     0.943743     0.000345765      2.10871
+ 0.000242835     0.970011     0.000360658      2.27606
+ 0.000248906     0.996742     0.000376609       2.4639
+ 0.000255129      1.02394     0.000393728      2.67544
+ 0.000261507       1.0516     0.000412135      2.91443
+ 0.000268045      1.07973     0.000431963      3.18521
+ 0.000274746      1.10833     0.000453355      3.49285
+ 0.000281615       1.1374     0.000476467      3.84319
+ 0.000288655      1.16696     0.000501464      4.24303
+ 0.000295871      1.19699     0.000528525      4.70016
+ 0.000303268       1.2275     0.000557836      5.22356
+  0.00031085      1.25849     0.000589594      5.82349
+ 0.000318621      1.28997     0.000624002      6.51164
+ 0.000326587      1.32194     0.000661271      7.30125
+ 0.000334751      1.35441     0.000701614      8.20721
+  0.00034312      1.38736     0.000745247      9.24621
+ 0.000351698      1.42081     0.000792386      10.4367
+  0.00036049      1.45476     0.000843244      11.7991
+ 0.000369503      1.48922     0.000898026      13.3553
+  0.00037874      1.52418      0.00095693      15.1293
+ 0.000388209      1.55964      0.00102014       17.146
+ 0.000397914      1.59562      0.00108782      19.4316
+ 0.000407862      1.63211      0.00116012      22.0127
+ 0.000418058      1.66911      0.00123716      24.9157
+  0.00042851      1.70663      0.00131903      28.1661
+ 0.000439223      1.74468      0.00140579      31.7871
+ 0.000450203      1.78325      0.00149746      35.7993
+ 0.000461458      1.82235      0.00159403      40.2188
+ 0.000472995      1.86197      0.00169546      45.0566
+  0.00048482      1.90213      0.00180164      50.3173
+  0.00049694      1.94283      0.00191246      55.9989
+ 0.000509364      1.98406      0.00202777      62.0916
+ 0.000522098      2.02584      0.00214739      68.5785
+  0.00053515      2.06816      0.00227112      75.4354
+ 0.000548529      2.11103      0.00239878      82.6323
+ 0.000562242      2.15444      0.00253017       90.134
+ 0.000576298      2.19841      0.00266511      97.9022
+ 0.000590706      2.24294      0.00280345      105.897
+ 0.000605473      2.28802      0.00294505      114.078
+  0.00062061      2.33367      0.00308982      122.408
+ 0.000636125      2.37988      0.00323771      130.851
+ 0.000652028      2.42665       0.0033887      139.378
+ 0.000668329        2.474      0.00354281      147.961
+ 0.000685037      2.52192      0.00370011       156.58
+ 0.000702163      2.57041       0.0038607      165.221
+ 0.000719717      2.61947      0.00402472      173.872
+  0.00073771      2.66912      0.00419232      182.529
+ 0.000756153      2.71935      0.00436369      191.191
+ 0.000775057      2.77016      0.00453903      199.858
+ 0.000794433      2.82156      0.00471857      208.537
+ 0.000814294      2.87354      0.00490255      217.234
+ 0.000834652      2.92612      0.00509121      225.958
+ 0.000855518      2.97928       0.0052848      234.721
+ 0.000876906      3.03304      0.00548359      243.532
+ 0.000898828       3.0874      0.00568784      252.403
+ 0.000921299      3.14235      0.00589783      261.346
+ 0.000944332      3.19791      0.00611383      270.373
+  0.00096794      3.25406      0.00633611      279.494
+ 0.000992138      3.31082      0.00656496       288.72
+  0.00101694      3.36817      0.00680065      298.063
+  0.00104237      3.42614      0.00704347      307.532
+  0.00106842      3.48471      0.00729371      317.136
+  0.00109514      3.54388      0.00755166      326.886
+  0.00112251      3.60367      0.00781761       336.79
+  0.00115058      3.66406      0.00809186      346.856
+  0.00117934      3.72507      0.00837472      357.091
+  0.00120882      3.78668      0.00866649      367.503
+  0.00123904      3.84891      0.00896749      378.098
+  0.00127002      3.91175      0.00927804      388.885
+  0.00130177      3.97519      0.00959846      399.867
+  0.00133432      4.03926      0.00992909      411.052
+  0.00136767      4.10393       0.0102703      422.445
+  0.00140187      4.16922       0.0106223      434.052
+  0.00143691      4.23512       0.0109857      445.876
+  0.00147284      4.30164       0.0113606      457.925
+  0.00150966      4.36876       0.0117475      470.201
+   0.0015474       4.4365       0.0121469      482.711
+  0.00158608      4.50485       0.0125589      495.458
+  0.00162573      4.57382       0.0129842      508.446
+  0.00166638      4.64339       0.0134231       521.68
+  0.00170804      4.71358        0.013876      535.164
+  0.00175074      4.78438       0.0143433      548.903
+  0.00179451      4.85578       0.0148256      562.899
+  0.00183937       4.9278       0.0153232      577.157
+  0.00188535      5.00042       0.0158368      591.681
+  0.00193249      5.07365       0.0163666      606.474
+   0.0019808      5.14748       0.0169134      621.541
+  0.00203032      5.22192       0.0174775      636.885
+  0.00208108      5.29696       0.0180595      652.509
+   0.0021331      5.37261         0.01866      668.418
+  0.00218643      5.44885       0.0192795      684.614
+  0.00224109       5.5257       0.0199187      701.103
+  0.00229712      5.60314        0.020578      717.886
+  0.00235455      5.68118       0.0212582      734.968
+  0.00241341      5.75981       0.0219599      752.353
+  0.00247375      5.83904       0.0226838      770.043
+  0.00253559      5.91886       0.0234304      788.043
+  0.00259898      5.99926       0.0242005      806.356
+  0.00266396      6.08026       0.0249949      824.985
+  0.00273055      6.16184       0.0258142      843.934
+  0.00279882        6.244       0.0266592      863.207
+  0.00286879      6.32675       0.0275307      882.806
+  0.00294051      6.41008       0.0284295      902.736
+  0.00301402      6.49398       0.0293564          923
+  0.00308937      6.57846       0.0303123      943.601
+  0.00316661      6.66352       0.0312981      964.543
+  0.00324577      6.74914       0.0323146       985.83
+  0.00332691      6.83534       0.0333627      1007.46
+  0.00341009       6.9221       0.0344435      1029.45
+  0.00349534      7.00943       0.0355579      1051.79
+  0.00358272      7.09732        0.036707      1074.49
+  0.00367229      7.18577       0.0378916      1097.55
+   0.0037641      7.27478       0.0391131      1120.97
+   0.0038582      7.36434       0.0403723      1144.77
+  0.00395466      7.45446       0.0416705      1168.93
+  0.00405352      7.54513       0.0430089      1193.47
+  0.00415486      7.63635       0.0443885      1218.39
+  0.00425873      7.72811       0.0458108      1243.69
+   0.0043652      7.82042       0.0472769      1269.38
+  0.00447433      7.91327       0.0487881      1295.45
+  0.00458619      8.00666       0.0503458      1321.92
+  0.00470084      8.10058       0.0519514      1348.78
+  0.00481836      8.19504       0.0536063      1376.05
+  0.00493882      8.29003        0.055312      1403.71
+  0.00506229      8.38555       0.0570699      1431.78
+  0.00518885       8.4816       0.0588817      1460.26
+  0.00531857      8.57817       0.0607489      1489.15
+  0.00545154      8.67527       0.0626731      1518.45
+  0.00558783      8.77288       0.0646561      1548.18
+  0.00572752      8.87101       0.0666996      1578.32
+  0.00587071      8.96966       0.0688054      1608.89
+  0.00601748      9.06882       0.0709754      1639.89
+  0.00616791      9.16849       0.0732113      1671.32
+  0.00632211      9.26866       0.0755152      1703.19
+  0.00648016      9.36934       0.0778891      1735.49
+  0.00664217      9.47052        0.080335      1768.23
+  0.00680822      9.57221       0.0828551      1801.42
+  0.00697843      9.67439       0.0854515      1835.05
+  0.00715289      9.77706       0.0881264      1869.14
+  0.00733171      9.88023       0.0908823      1903.68
+    0.007515      9.98389       0.0937214      1938.67
+  0.00770288       10.088       0.0966462      1974.13
+  0.00789545      10.1927       0.0996593      2010.05
+  0.00809284      10.2978        0.102763      2046.43
+  0.00829516      10.4034         0.10596      2083.28
+  0.00850254      10.5095        0.109254      2120.61
+   0.0087151       10.616        0.112646      2158.41
+  0.00893298      10.7231        0.116141      2196.68
+   0.0091563      10.8306         0.11974      2235.44
+  0.00938521      10.9385        0.123447      2274.68
+  0.00961984       11.047        0.127265      2314.41
+  0.00986034      11.1559        0.131198      2354.63
+   0.0101068      11.2652        0.135248      2395.34
+   0.0103595      11.3751        0.139419      2436.54
+   0.0106185      11.4854        0.143715      2478.24
+    0.010884      11.5961        0.148139      2520.45
+   0.0111561      11.7073        0.152695      2563.16
+    0.011435       11.819        0.157387      2606.37
+   0.0117208      11.9311        0.162219       2650.1
+   0.0120139      12.0436        0.167194      2694.33
+   0.0123142      12.1566        0.172317      2739.09
+   0.0126221      12.2701        0.177592      2784.36
+   0.0129376       12.384        0.183024      2830.15
+   0.0132611      12.4983        0.188617      2876.46
+   0.0135926      12.6131        0.194376       2923.3
+   0.0139324      12.7283        0.200305      2970.67
+   0.0142807      12.8439         0.20641      3018.57
+   0.0146377        12.96        0.212696         3067
+   0.0150037      13.0765        0.219167      3115.98
+   0.0153788      13.1934        0.225829      3165.49
+   0.0157632      13.3107        0.232688      3215.54
+   0.0161573      13.4285         0.23975      3266.14
+   0.0165612      13.5467        0.247019      3317.29
+   0.0169753      13.6653        0.254503      3368.98
+   0.0173997      13.7844        0.262207      3421.23
+   0.0178346      13.9039        0.270137      3474.03
+   0.0182805      14.0237        0.278301       3527.4
+   0.0187375       14.144        0.286704      3581.32
+    0.019206      14.2647        0.295354       3635.8
+   0.0196861      14.3858        0.304258      3690.85
+   0.0201783      14.5074        0.313422      3746.47
+   0.0206827      14.6293        0.322856      3802.66
+   0.0211998      14.7516        0.332565      3859.42
+   0.0217298      14.8744        0.342558      3916.76
+    0.022273      14.9975        0.352844      3974.67
+   0.0228299      15.1211         0.36343      4033.17
+   0.0234006       15.245        0.374326      4092.25
+   0.0239856      15.3693        0.385539      4151.91
+   0.0245853      15.4941         0.39708      4212.17
+   0.0251999      15.6192        0.408956      4273.01
+   0.0258299      15.7447        0.421179      4334.44
+   0.0264756      15.8706        0.433758      4396.47
+   0.0271375      15.9969        0.446702       4459.1
+    0.027816      16.1236        0.460024      4522.32
+   0.0285114      16.2507        0.473732      4586.15
+   0.0292241      16.3781        0.487838      4650.59
+   0.0299547       16.506        0.502354      4715.63
+   0.0307036      16.6342         0.51729      4781.28
+   0.0314712      16.7628         0.53266      4847.54
+    0.032258      16.8918        0.548476      4914.41
+   0.0330644      17.0211        0.564749      4981.91
+   0.0338911      17.1509        0.581493      5050.02
+   0.0347383       17.281        0.598722      5118.75
+   0.0356068      17.4114        0.616448       5188.1
+    0.036497      17.5423        0.634687      5258.08
+   0.0374094      17.6735        0.653453      5328.69
+   0.0383446      17.8051         0.67276      5399.93
+   0.0393032      17.9371        0.692625       5471.8
+   0.0402858      18.0694        0.713062       5544.3
+    0.041293      18.2021        0.734088      5617.44
+   0.0423253      18.3351        0.755719      5691.22
+   0.0433834      18.4685        0.777973      5765.64
+    0.044468      18.6023        0.800868      5840.71
+   0.0455797      18.7364        0.824421      5916.42
+   0.0467192      18.8709         0.84865      5992.78
+   0.0478872      19.0058        0.873576      6069.79
+   0.0490843       19.141        0.899218      6147.45
+   0.0503115      19.2765        0.925595      6225.77
+   0.0515692      19.4124        0.952729      6304.74
+   0.0528585      19.5487        0.980641      6384.37
+   0.0541799      19.6853         1.00935      6464.67
+   0.0555344      19.8222         1.03889      6545.62
+   0.0569228      19.9595         1.06927      6627.25
+   0.0583459      20.0972         1.10051      6709.54
+   0.0598045      20.2352         1.13266       6792.5
+   0.0612996      20.3735         1.16572      6876.13
+   0.0628321      20.5122         1.19972      6960.43
+   0.0644029      20.6512          1.2347      7045.42
+    0.066013      20.7906         1.27068      7131.08
+   0.0676633      20.9303         1.30768      7217.42
+   0.0693549      21.0703         1.34573      7304.45
+   0.0710888      21.2107         1.38488      7392.15
+    0.072866      21.3514         1.42513      7480.55
+   0.0746876      21.4924         1.46654      7569.64
+   0.0765548      21.6338         1.50912      7659.41
+   0.0784687      21.7755         1.55291      7749.88
+   0.0804304      21.9176         1.59795      7841.05
+   0.0824412      22.0599         1.64427      7932.91
+   0.0845022      22.2026         1.69191      8025.47
+   0.0866148      22.3456         1.74089      8118.74
+   0.0887801       22.489         1.79127       8212.7
+   0.0909996      22.6327         1.84308      8307.38
+   0.0932746      22.7767         1.89636      8402.76
+   0.0956065       22.921         1.95115      8498.85
+   0.0979967      23.0656         2.00749      8595.65
+    0.100447      23.2106         2.06543      8693.17
+    0.102958      23.3558         2.12501       8791.4
+    0.105532      23.5014         2.18628      8890.35
+     0.10817      23.6473         2.24928      8990.02
+    0.110874      23.7936         2.31406      9090.42
+    0.113646      23.9401         2.38067      9191.53
+    0.116487       24.087         2.44917      9293.38
+    0.119399      24.2341          2.5196      9395.95
+    0.122384      24.3816         2.59202      9499.25
+    0.125444      24.5294         2.66648      9603.28
+     0.12858      24.6775         2.74304      9708.05
+    0.131795      24.8259         2.82177      9813.56
+    0.135089      24.9746         2.90271       9919.8
+    0.138467      25.1236         2.98593      10026.8
+    0.141928       25.273          3.0715      10134.5
+    0.145477      25.4226         3.15948        10243
+    0.149113      25.5725         3.24994      10352.2
+    0.152841      25.7228         3.34294      10462.2
+    0.156662      25.8733         3.43855      10572.9
+    0.160579      26.0241         3.53686      10684.3
+    0.164593      26.1753         3.63793      10796.5
+    0.168708      26.3267         3.74184      10909.5
+    0.172926      26.4784         3.84866      11023.3
+    0.177249      26.6304         3.95849      11137.7
+     0.18168      26.7827          4.0714        11253
+    0.186222      26.9354         4.18747        11369
+    0.190878      27.0883         4.30681      11485.8
+     0.19565      27.2414         4.42948      11603.3
+    0.200541      27.3949          4.5556      11721.7
+    0.205555      27.5487         4.68525      11840.8
+    0.210693      27.7028         4.81853      11960.6
+    0.215961      27.8571         4.95554      12081.3
+     0.22136      28.0117         5.09639      12202.7
+    0.226894      28.1667         5.24117      12324.9
+    0.232566      28.3219         5.39001      12447.8
+     0.23838      28.4773         5.54301      12571.6
+     0.24434      28.6331         5.70028      12696.1
+    0.250448      28.7891         5.86195      12821.5
+     0.25671      28.9455         6.02813      12947.6
+    0.263127      29.1021         6.19896      13074.5
+    0.269705       29.259         6.37455      13202.2
+    0.276448      29.4161         6.55504      13330.7
+    0.283359      29.5736         6.74056        13460
+    0.290443      29.7313         6.93126      13590.1
+    0.297704      29.8893         7.12728      13720.9
+    0.305147      30.0475         7.32875      13852.6
+    0.312776      30.2061         7.53584      13985.1
+    0.320595      30.3649          7.7487      14118.4
+     0.32861      30.5239         7.96748      14252.5
+    0.336825      30.6833         8.19235      14387.4
+    0.345246      30.8429         8.42348      14523.1
+    0.353877      31.0028         8.66104      14659.7
+    0.362724      31.1629          8.9052        14797
+    0.371792      31.3233         9.15615      14935.2
+    0.381087       31.484         9.41407      15074.1
+    0.390614      31.6449         9.67916      15213.9
+    0.400379      31.8061         9.95161      15354.5
+    0.410389      31.9676         10.2316        15496
+    0.420648      32.1293         10.5194      15638.2
+    0.431165      32.2913         10.8152      15781.3
+    0.441944      32.4535         11.1191      15925.2
+    0.452992       32.616         11.4315        16070
+    0.464317      32.7788         11.7526      16215.6
+    0.475925      32.9418         12.0826        16362
+    0.487823      33.1051         12.4217      16509.2
+    0.500019      33.2686         12.7702      16657.3
+    0.512519      33.4324         13.1283      16806.2
+    0.525332      33.5964         13.4964        16956
+    0.538466      33.7607         13.8746      17106.6
+    0.551927      33.9252         14.2633        17258
+    0.565725        34.09         14.6628      17410.3
+    0.579869       34.255         15.0733      17563.4
+    0.594365      34.4203         15.4951      17717.4
+    0.609224      34.5858         15.9286      17872.2
+    0.624455      34.7515         16.3741      18027.9
+    0.640066      34.9176         16.8319      18184.5
+    0.656068      35.0838         17.3023      18341.8
+     0.67247      35.2503         17.7857      18500.1
+    0.689281       35.417         18.2825      18659.2
+    0.706514       35.584          18.793      18819.2
+    0.724176      35.7512         19.3175        18980
+    0.742281      35.9187         19.8565      19141.7
+    0.760838      36.0864         20.4104      19304.2
+    0.779859      36.2543         20.9795      19467.7
+    0.799355      36.4225         21.5643        19632
+    0.819339      36.5909         22.1652      19797.1
+    0.839823      36.7595         22.7827      19963.1
+    0.860818      36.9284         23.4171      20130.1
+    0.882339      37.0975          24.069      20297.8
+    0.904397      37.2668         24.7389      20466.5
+    0.927007      37.4364         25.4272        20636
+    0.950182      37.6062         26.1344      20806.4
+    0.973937      37.7762         26.8611      20977.7
+    0.998285      37.9464         27.6077      21149.9
+     1.02324      38.1169         28.3749      21322.9
+     1.04882      38.2876         29.1631      21496.9
+     1.07504      38.4585          29.973      21671.7
+     1.10192      38.6297         30.8052      21847.4
+     1.12947      38.8011         31.6601        22024
+      1.1577      38.9727         32.5386      22201.5
+     1.18665      39.1445         33.4411      22379.9
+     1.21631      39.3165         34.3684      22559.2
+     1.24672      39.4888         35.3212      22739.4
+     1.27789      39.6613         36.3001      22920.5
+     1.30984       39.834         37.3058      23102.5
+     1.34258      40.0069         38.3391      23285.3
+     1.37615        40.18         39.4006      23469.1
+     1.41055      40.3534         40.4913      23653.8
+     1.44581      40.5269         41.6118      23839.4
+     1.48196      40.7007         42.7631      24025.9
+     1.51901      40.8747         43.9458      24213.3
+     1.55698      41.0489         45.1609      24401.6
+     1.59591      41.2233         46.4093      24590.8
+     1.63581      41.3979         47.6918        24781
+      1.6767      41.5728         49.0094        24972
+     1.71862      41.7478          50.363        25164
+     1.76158       41.923         51.7536      25356.8
+     1.80562      42.0985         53.1823      25550.6
+     1.85076      42.2742           54.65      25745.4
+     1.89703        42.45         56.1577        25941
+     1.94446      42.6261         57.7067      26137.6
+     1.99307      42.8024         59.2979        26335
+      2.0429      42.9788         60.9326      26533.4
+     2.09397      43.1555          62.612      26732.8
+     2.14632      43.3324         64.3371        26933
+     2.19998      43.5095         66.1093      27134.2
+     2.25498      43.6867         67.9299      27336.4
+     2.31135      43.8642         69.8001      27539.4
+     2.36914      44.0419         71.7213      27743.4
+     2.42836      44.2197         73.6949      27948.3
+     2.48907      44.3978         75.7223      28154.2
+      2.5513      44.5761         77.8049        28361
+     2.61508      44.7545         79.9442      28568.7
+     2.68046      44.9332         82.1419      28777.4
+     2.74747       45.112         84.3993        28987
+     2.81616       45.291         86.7183      29197.5
+     2.88656      45.4702         89.1003        29409
+     2.95873      45.6496         91.5472      29621.4
+     3.03269      45.8292         94.0606      29834.8
+     3.10851       46.009         96.6425      30049.2
+     3.18622       46.189         99.2945      30264.5
+     3.26588      46.3691         102.019      30480.7
+     3.34753      46.5495         104.817      30697.9
+     3.43121        46.73         107.691        30916
+     3.51699      46.9107         110.644      31135.1
+     3.60492      47.0916         113.676      31355.1
+     3.69504      47.2727         116.791      31576.1
+     3.78742       47.454         119.991      31798.1
+      3.8821      47.6354         123.277        32021
+     3.97916       47.817         126.653      32244.9
+     4.07864      47.9988          130.12      32469.7
+      4.1806      48.1808         133.682      32695.5
+     4.28512      48.3629          137.34      32922.3
+     4.39224      48.5452         141.097        33150
+     4.50205      48.7277         144.957      33378.7
+      4.6146      48.9104          148.92      33608.4
+     4.72997      49.0933         152.992        33839
+     4.84822      49.2763         157.174      34070.6
+     4.96942      49.4595         161.469      34303.2
+     5.09366      49.6429          165.88      34536.7
+       5.221      49.8264         170.411      34771.2
+     5.35152      50.0101         175.065      35006.7
+     5.48531       50.194         179.844      35243.1
+     5.62244       50.378         184.754      35480.6
+     5.76301      50.5622         189.796        35719
+     5.90708      50.7466         194.974      35958.4
+     6.05476      50.9312         200.293      36198.8
+     6.20613      51.1159         205.755      36440.1
diff --git a/examples/cosmo_box_gravity_only_3d/Masses_L50n32_z0.txt b/examples/cosmo_box_gravity_only_3d/Masses_L50n32_z0.txt
new file mode 100644
index 0000000000000000000000000000000000000000..53b34536715e793d85284f27997ecb30eac944ba
--- /dev/null
+++ b/examples/cosmo_box_gravity_only_3d/Masses_L50n32_z0.txt
@@ -0,0 +1,62 @@
+4.222264453125000000e+14
+1.860935937500000000e+14
+9.680791992187500000e+13
+9.419149414062500000e+13
+8.993979492187500000e+13
+8.568809570312500000e+13
+8.372577148437500000e+13
+7.293299316406250000e+13
+6.671896972656250000e+13
+6.606486328125000000e+13
+6.148611328125000000e+13
+6.115905761718750000e+13
+4.578752929687500000e+13
+4.088172363281250000e+13
+3.957350830078125000e+13
+3.761118408203125000e+13
+3.630297119140625000e+13
+3.139716308593750000e+13
+2.878073242187500000e+13
+2.420197998046875000e+13
+2.387492675781250000e+13
+2.354787353515625000e+13
+2.256671142578125000e+13
+2.223965820312500000e+13
+2.191260253906250000e+13
+2.093144287109375000e+13
+2.093144287109375000e+13
+2.060438720703125000e+13
+2.027733520507812500e+13
+1.962322753906250000e+13
+1.962322753906250000e+13
+1.896911987304687500e+13
+1.831501220703125000e+13
+1.831501220703125000e+13
+1.733385009765625000e+13
+1.733385009765625000e+13
+1.733385009765625000e+13
+1.700679687500000000e+13
+1.667974243164062500e+13
+1.602563598632812500e+13
+1.602563598632812500e+13
+1.569858154296875000e+13
+1.537152832031250000e+13
+1.504447387695312500e+13
+1.504447387695312500e+13
+1.373625854492187500e+13
+1.275509765625000000e+13
+1.275509765625000000e+13
+1.242804321289062500e+13
+1.242804321289062500e+13
+1.210098999023437500e+13
+1.210098999023437500e+13
+1.144688232421875000e+13
+1.144688232421875000e+13
+1.144688232421875000e+13
+1.111982910156250000e+13
+1.111982910156250000e+13
+1.111982910156250000e+13
+1.046572143554687500e+13
+1.046572143554687500e+13
+1.046572143554687500e+13
+1.046572143554687500e+13
diff --git a/examples/cosmo_box_gravity_only_3d/Masses_L50n32_z1.txt b/examples/cosmo_box_gravity_only_3d/Masses_L50n32_z1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..b92550d8cdef0f2df01f6e9cb11dcb2eb2de6bd3
--- /dev/null
+++ b/examples/cosmo_box_gravity_only_3d/Masses_L50n32_z1.txt
@@ -0,0 +1,25 @@
+1.040031054687500000e+14
+6.868129394531250000e+13
+6.606486328125000000e+13
+5.429092773437500000e+13
+3.663002441406250000e+13
+3.466770019531250000e+13
+2.976189453125000000e+13
+2.910778564453125000e+13
+2.845367919921875000e+13
+2.191260253906250000e+13
+2.060438720703125000e+13
+1.929617309570312500e+13
+1.896911987304687500e+13
+1.700679687500000000e+13
+1.635268920898437500e+13
+1.504447387695312500e+13
+1.504447387695312500e+13
+1.504447387695312500e+13
+1.504447387695312500e+13
+1.308215087890625000e+13
+1.275509765625000000e+13
+1.242804321289062500e+13
+1.177393676757812500e+13
+1.111982910156250000e+13
+1.079277465820312500e+13
diff --git a/examples/cosmo_box_gravity_only_3d/check.py b/examples/cosmo_box_gravity_only_3d/check.py
new file mode 100644
index 0000000000000000000000000000000000000000..224b49c1ca6399c7217f4ce0f438935c0339f5c6
--- /dev/null
+++ b/examples/cosmo_box_gravity_only_3d/check.py
@@ -0,0 +1,106 @@
+""" @package ./examples/cosmo_box_gravity_only_3d/check.py
+Code that checks results of gravity only structure formation simulation
+
+created by Rainer Weinberger, last modified 25.02.2019
+"""
+
+""" load libraries """
+import sys    ## load sys; needed for exit codes
+import numpy as np    ## load numpy
+import h5py    ## load h5py; needed to read snapshots
+import matplotlib.pyplot as plt    ## plot stuff
+
+simulation_directory = str(sys.argv[1])
+print("examples/cosmo_box_gravity_only_3d/check.py: checking simulation output in directory " + simulation_directory) 
+
+FloatType = np.float64  # double precision: np.float64, for single use np.float32
+
+Boxsize = 50 ##Mpc/h
+HubbleParam = 0.6774
+UnitMass = 1.0e10
+Volume = Boxsize * Boxsize * Boxsize / HubbleParam / HubbleParam / HubbleParam
+
+Redshifts = [1, 0]
+status = 0
+
+CompareAgainstReferenceRun = True ## comparison for small L50m32 box; deactivate this when comparing against self-created ICs
+createFigures = True
+
+for i_file, z in enumerate(Redshifts):
+    """ try to read in snapshot """
+    directory = simulation_directory+"/output/"
+    filename = "fof_subhalo_tab_%03d.hdf5" % (i_file)
+    try:
+        data = h5py.File(directory+filename, "r")
+    except:
+        print("could not open "+directory+filename)
+        sys.exit(1)
+    
+    """ get simulation data """
+    ## simulation data
+    GrpPos = np.array(data["Group"]["GroupPos"], dtype=FloatType) / HubbleParam / 1000.
+    GrpR200c = np.array(data["Group"]["Group_R_Crit200"], dtype=FloatType) / HubbleParam / 1000.
+    M200c = np.array(data["Group"]["GroupMass"], dtype=FloatType) * UnitMass
+    M200c = np.sort(M200c)[::-1]
+    CumMassFunction = np.cumsum(np.ones(M200c.shape) ) / Volume
+    
+    if CompareAgainstReferenceRun:
+        ## comparison to reference run (sorted list of M200)
+        M200c_ref = np.loadtxt("./examples/cosmo_box_gravity_only_3d/Masses_L50n32_z%.1d.txt"% z)
+        
+        minLen = np.min([len(M200c), len(M200c_ref)])
+        i_select = np.arange(minLen)
+        
+        delta = (M200c[i_select]-M200c_ref[i_select]) / M200c_ref[i_select]
+        
+        ## empirically based tolerances
+        tolerance_average = 0.01
+        tolerance_std = 0.05
+        if np.abs(np.average(delta)) > tolerance_average or np.abs(np.std(delta)) > tolerance_std:
+            status = 1
+            print("ERROR: z=%g difference in halo masses exceeding limits!" % z)
+            print("relative mass error (=delta)")
+            print(delta)
+            print("average delta (tolerance: %g)" % tolerance_average)
+            print(np.average(delta))
+            print("stddev delta (tolerance: %g)" % tolerance_std)
+            print(np.std(delta))
+    
+    """ optional figure """
+    if createFigures:
+        filename = "snap_%03d.hdf5" % (i_file)
+        try:
+            data = h5py.File(directory+filename, "r")
+        except:
+            print("could not open "+directory+filename)
+            sys.exit(1)
+        pos = np.array(data["PartType1"]["Coordinates"], dtype=FloatType) / HubbleParam / 1000.
+    
+        fig = plt.figure(figsize=(6.9,6.9))
+        ax = plt.axes([0.1,0.1,0.87,0.87])
+        
+        if(pos.shape[0] > 32**3):
+            i_select = np.random.uniform(low=0.0, high=pos.shape[0], size=32**3).astype(np.int)
+        else:
+            i_select = np.arange(pos.shape[0])
+        ax.scatter(pos[i_select, 0], pos[i_select, 1], marker='.', s=0.05, alpha=0.5, rasterized=True)
+        for i in np.arange(GrpR200c.shape[0]):
+            ax.add_artist(plt.Circle((GrpPos[i,0], GrpPos[i,1]), GrpR200c[i], color='k', fill=False))
+        
+        ax.set_xlim([0,Boxsize/HubbleParam])
+        ax.set_ylim([0,Boxsize/HubbleParam])
+        ax.set_xlabel('[Mpc]')
+        ax.set_ylabel('[Mpc]')
+        
+        bx = plt.axes([0.70,0.74,0.26,0.22])
+        bx.plot(M200c, CumMassFunction)
+        bx.set_xscale('log')
+        bx.set_yscale('log')
+        bx.set_xlim([9e12,5e14])
+        bx.set_ylim([9e-7,2e-4])
+        bx.set_xlabel(r"M$_{200,c}$ [M$_\odot$]")
+        bx.set_ylabel(r"$n$(>M) [Mpc$^{-3}$]")
+        fig.savefig(simulation_directory+'/largeScaleStructure_z%.1d.pdf'%z, dpi=300)
+
+## if everything is ok: 0 else: 1
+sys.exit(status)
diff --git a/examples/cosmo_box_gravity_only_3d/create.py b/examples/cosmo_box_gravity_only_3d/create.py
new file mode 100644
index 0000000000000000000000000000000000000000..dfd3c2c0190c1aba9504be6256702b1df716487d
--- /dev/null
+++ b/examples/cosmo_box_gravity_only_3d/create.py
@@ -0,0 +1,82 @@
+""" @package examples/cosmo_box_gravity_only_3d/create.py
+Code that creates 3d cosmologiacl box ICs;
+some ICs provided, but can be created also at startup if 
+ic_creation is set to 'music' or 'ngenic'.
+
+created by Rainer Weinberger, last modified 25.02.2019
+"""
+
+
+""" load libraries """
+import sys    # needed for exit codes
+import numpy as np    # scientific computing package
+import h5py    # hdf5 format
+import os  # operating system interface
+from subprocess import call # execute bash commands
+
+## create new ics with 'music' or 'ngenic' or just 'copy' existing ones to the run directory
+ic_creation='copy'
+
+
+""" input """
+simulation_directory = str(sys.argv[1])
+print("examples/cosmo_box_gravity_only_3d/create.py " + simulation_directory)
+
+
+""" initial conditions: either copy or create with code """
+if ic_creation == 'copy':
+    ## copy and use provided initial conditions
+    call(['cp', './examples/cosmo_box_gravity_only_3d/L50n32/ics', simulation_directory+'/ics'])
+    
+elif ic_creation == 'music':
+    ## create new initial conditions with the MUSIC code
+    status = call(['hg', 'clone', 'https://bitbucket.org/ohahn/music', simulation_directory+'/music'])
+    if status != 0:
+        print('CREATE: ERROR: hg clone failed!')
+        sys.exit(status)
+    cwd = os.getcwd()
+    os.chdir(simulation_directory+'/music/')
+    status = call(['make'])
+    if status != 0:
+        print('CREATE: ERROR: make failed!')
+        sys.exit(status)
+    status = call(['./MUSIC',cwd+'/examples/cosmo_box_gravity_only_3d/param_music.txt'])
+    if status != 0:
+        print('CREATE: ERROR: execution failed!')
+        sys.exit(status)
+    os.chdir(cwd)
+    
+elif ic_creation == 'ngenic':
+    ## create new initial conditions with the N-GenIC code
+    status = call(['git', 'clone', 'https://gitlab.mpcdf.mpg.de/ext-c2c74fbfcdff/ngenic.git', simulation_directory+'/ngenic'])
+    if status != 0:
+        print('CREATE: ERROR: git clone failed!')
+        sys.exit(status)
+    cwd = os.getcwd()
+    os.chdir(simulation_directory+'/ngenic/')
+    status = call(['make'])
+    if status != 0:
+        print('CREATE: ERROR: make failed!')
+        sys.exit(status)
+    status = call(['mpiexec','-np','1','./N-GenIC',cwd+'/examples/cosmo_box_gravity_only_3d/param_ngenic.txt'])
+    if status != 0:
+        print('CREATE: ERROR: execution failed!')
+        sys.exit(status)
+    os.chdir(cwd)
+else:
+    print("CREATE: ERROR: no valid option for ic creation! choose 'copy', 'music' or 'ngenic'")
+    exit(1)
+
+
+""" set output times z=1,0"""
+outputTimes = np.array([0.5, 1], dtype=np.float64)
+ones = np.ones(outputTimes.shape, dtype=np.int)
+
+
+""" write output list file """
+data = np.array([outputTimes, ones]).T
+np.savetxt(simulation_directory+"/output_list.txt",data, fmt="%g %1.f" )
+
+
+""" normal exit """
+sys.exit(0) 
diff --git a/examples/cosmo_box_gravity_only_3d/param.txt b/examples/cosmo_box_gravity_only_3d/param.txt
new file mode 100644
index 0000000000000000000000000000000000000000..389a23f3cf6acb84f900c44fb9ead3471f012529
--- /dev/null
+++ b/examples/cosmo_box_gravity_only_3d/param.txt
@@ -0,0 +1,107 @@
+%----  Relevant files
+InitCondFile                          run/examples/cosmo_box_gravity_only_3d/ics
+OutputDir                             run/examples/cosmo_box_gravity_only_3d/output
+SnapshotFileBase                      snap
+OutputListFilename                    run/examples/cosmo_box_gravity_only_3d/output_list.txt
+
+%---- File formats
+ICFormat                              1
+SnapFormat                            3
+
+%---- CPU-time limits
+TimeLimitCPU                          93000
+CpuTimeBetRestartFile                 12000
+FlushCpuTimeDiff                      120
+
+ResubmitOn                            0
+ResubmitCommand                       my-scriptfile
+
+%----- Memory alloction
+MaxMemSize                            2500
+
+%---- Caracteristics of run
+TimeBegin                             0.0078125 % Begin of the simulation z=127
+TimeMax                               1.0 % End of the simulation z=0
+
+%---- Basic code options that set the type of simulation
+ComovingIntegrationOn                 1
+PeriodicBoundariesOn                  1
+CoolingOn                             0
+StarformationOn                       0
+
+%---- Cosmological parameters (Planck 2016 cosmology)
+Omega0                                0.3089
+OmegaLambda                           0.6911
+OmegaBaryon                           0.0     %0.0486
+HubbleParam                           0.6774
+BoxSize                               50000.0
+
+%---- Output frequency and output parameters
+OutputListOn                          1
+TimeBetSnapshot                       0.0
+TimeOfFirstSnapshot                   0.0
+TimeBetStatistics                     0.01
+NumFilesPerSnapshot                   1
+NumFilesWrittenInParallel             1
+
+%---- Accuracy of time integration
+TypeOfTimestepCriterion               0
+ErrTolIntAccuracy                     0.012
+CourantFac                            0.3
+MaxSizeTimestep                       0.005
+MinSizeTimestep                       2.0e-9
+
+
+%---- Treatment of empty space and temperature limits
+InitGasTemp                           244.8095
+MinGasTemp                            5.0
+MinimumDensityOnStartUp               1.0e-20
+LimitUBelowThisDensity                0.0
+LimitUBelowCertainDensityToThisValue  0.0
+MinEgySpec                            0.0
+
+%---- Tree algorithm, force accuracy, domain update frequency
+TypeOfOpeningCriterion                1
+ErrTolTheta                           0.7
+ErrTolForceAcc                        0.0025
+MultipleDomains                       4
+TopNodeFactor                         2.5
+ActivePartFracForNewDomainDecomp      0.01
+ 
+%---- Initial density estimate
+DesNumNgb                             64
+MaxNumNgbDeviation                    4
+
+%---- System of units
+UnitLength_in_cm                      3.085678e21    %  1.0 kpc
+UnitMass_in_g                         1.989e43       %  1.0e10 solar masses
+UnitVelocity_in_cm_per_s              1e5            %  1 km/sec
+GravityConstantInternal               0
+
+%---- Gravitational softening lengths
+SofteningComovingType0                40.0
+SofteningComovingType1                40.0
+
+SofteningMaxPhysType0                 20.0
+SofteningMaxPhysType1                 20.0
+
+GasSoftFactor                         2.5
+
+SofteningTypeOfPartType0              0
+SofteningTypeOfPartType1              1
+SofteningTypeOfPartType2              1
+SofteningTypeOfPartType3              1
+SofteningTypeOfPartType4              1
+SofteningTypeOfPartType5              1
+
+
+MinimumComovingHydroSoftening         1.0
+AdaptiveHydroSofteningSpacing         1.2
+
+%----- Mesh regularization options
+CellShapingSpeed                      0.5
+CellShapingFactor                     1.0
+
+%----- Subfind
+ErrTolThetaSubfind                    0.7
+DesLinkNgb                            20
diff --git a/examples/cosmo_box_gravity_only_3d/param_music.txt b/examples/cosmo_box_gravity_only_3d/param_music.txt
new file mode 100644
index 0000000000000000000000000000000000000000..481013bb95caa91237961e89d2882fa2ad06f238
--- /dev/null
+++ b/examples/cosmo_box_gravity_only_3d/param_music.txt
@@ -0,0 +1,46 @@
+[setup]
+boxlength          = 50
+zstart             = 127
+levelmin           = 5
+levelmin_TF        = 5
+levelmax           = 5
+padding            = 8
+overlap            = 4
+ref_center         = 0.5, 0.5, 0.5
+ref_extent         = 0.4, 0.4, 0.4
+align_top          = no
+baryons            = no
+use_2LPT           = no
+use_LLA            = no
+periodic_TF        = yes
+[cosmology]
+Omega_m            = 0.3089
+Omega_L            = 0.6911
+w0                 = -1.0
+wa                 = 0.0
+Omega_b            = 0.0486
+H0                 = 67.74
+sigma_8            = 0.831
+nspec              = 0.9645
+transfer           = eisenstein
+[random]
+seed[7]            = 12345
+seed[8]            = 23456
+seed[9]            = 34567
+seed[10]           = 45678
+seed[11]           = 56789
+seed[12]           = 67890
+[output]
+#Gadget-2 (type=1: high-res particles, type=5: rest)
+format             = gadget2
+filename           = ../ics
+gadget_coarsetype  = 2
+gadget_usekpc      = yes
+[poisson]
+fft_fine           = yes
+accuracy           = 1e-5
+pre_smooth         = 3
+post_smooth        = 3
+smoother           = gs
+laplace_order      = 6
+grad_order         = 6
\ No newline at end of file
diff --git a/examples/cosmo_box_gravity_only_3d/param_ngenic.txt b/examples/cosmo_box_gravity_only_3d/param_ngenic.txt
new file mode 100644
index 0000000000000000000000000000000000000000..b95eba39dd2a9c2b737959632de21ea2959b5d4e
--- /dev/null
+++ b/examples/cosmo_box_gravity_only_3d/param_ngenic.txt
@@ -0,0 +1,82 @@
+
+Nmesh            128                        % This is the size of the FFT grid used to 
+                                            % compute the displacement field. One
+                                            % should have Nmesh >= Nsample.
+
+Nsample          128                        % sets the maximum k that the code uses,
+                                            % i.e. this effectively determines the
+                                            % Nyquist frequency that the code assumes,
+                                            % k_Nyquist = 2*PI/Box * Nsample/2
+                                            % Normally, one chooses Nsample such that
+                                            % Ntot =  Nsample^3, where Ntot is the
+                                            % total number of particles
+ 
+
+Box              50000.0                    % Periodic box size of simulation
+FileBase         ics                        % Base-filename of output files
+OutputDir        ../                        % Directory for output
+GlassFile        dummy_glass.dat            % File with unperturbed glass or
+                                            % Cartesian grid
+TileFac          4                          % Number of times the glass file is
+                                            % tiled in each dimension (must be
+                                            % an integer)
+
+
+Omega            0.3089                     % Total matter density  (at z=0)
+OmegaLambda      0.6911                     % Cosmological constant (at z=0)
+OmegaBaryon      0.0                        % Baryon density        (at z=0)
+HubbleParam      0.6774                     % Hubble paramater (may be used for power spec parameterization)
+Redshift         127                        % Starting redshift
+Sigma8           0.831                      % power spectrum normalization
+
+
+SphereMode       1                          % if "1" only modes with |k| < k_Nyquist are
+                                            % used (i.e. a sphere in k-space), otherwise modes with
+                                            % |k_x|,|k_y|,|k_z| < k_Nyquist are used
+                                            % (i.e. a cube in k-space)
+
+
+WhichSpectrum    1                          % "1" selects Eisenstein & Hu spectrum,
+                                            % "2" selects a tabulated power spectrum in
+                                            % the file 'FileWithInputSpectrum'
+                                            % otherwise, Efstathiou parametrization is used
+
+
+FileWithInputSpectrum   input_spectrum.txt  % filename of tabulated input
+                                            % spectrum (if used)
+InputSpectrum_UnitLength_in_cm  3.085678e24 % defines length unit of tabulated
+                                            % input spectrum in cm/h. 
+                                            % Note: This can be chosen different from UnitLength_in_cm
+
+ReNormalizeInputSpectrum   1                % if set to zero, the
+                                            % tabulated spectrum is
+                                            % assumed to be normalized
+                                            % already in its amplitude to
+                                            % the starting redshift,
+                                            % otherwise this is recomputed
+                                            % based on the specified sigma8
+
+
+ShapeGamma       0.21                       % only needed for Efstathiou power spectrum 
+PrimordialIndex  0.9645                     % may be used to tilt the primordial index, 
+                                            % primordial spectrum is k^PrimordialIndex
+
+
+Seed             123456                     %  seed for IC-generator
+
+
+NumFilesWrittenInParallel 1                 % limits the number of files that are
+                                            % written in parallel when outputting
+
+
+UnitLength_in_cm          3.085678e21       % defines length unit of output (in cm/h) 
+UnitMass_in_g             1.989e43          % defines mass unit of output (in g/cm)
+UnitVelocity_in_cm_per_s  1e5               % defines velocity unit of output (in cm/sec)
+
+
+
+
+
+
+
+
diff --git a/test.sh b/test.sh
index 4186b518774acd6658c801003fdb65502b693511..0eec03dc80bea9388bc3d42ff1917ad6d64181df 100644
--- a/test.sh
+++ b/test.sh
@@ -23,6 +23,7 @@ TESTS+="yee_2d "
 
 ## available 3d examples
 TESTS+="noh_3d "
+TESTS+="cosmo_box_gravity_only_3d "
 
 ## loop over all tests
 for TEST in $TESTS