Implement tunable option eigenvalues_only

src/elpa1/elpa1_template.X90

@@ -108,6 +108,7 @@ function elpa_solve_evp_&
    character(200)                                  :: errorMessage
    integer(kind=ik)                                :: na, nev, lda, ldq, nblk, matrixCols, &
                                                       mpi_comm_rows, mpi_comm_cols, mpi_comm_all
+   integer(kind=ik)                                :: eigenvalues_only
 
    call obj%timer%start("elpa_solve_evp_&
    &MATH_DATATYPE&
@@ -238,6 +239,12 @@ function elpa_solve_evp_&
    call obj%timer%stop("solve")
    if (.not.(success)) return
 
+   call obj%get("eigenvalues_only",eigenvalues_only)
+   if (eigenvalues_only .eq. 1) then
+     q(obj%local_nrows,obj%local_ncols) = 0.0
+     return
+   endif
+
 #if COMPLEXCASE == 1
    q(1:l_rows,1:l_cols_nev) = q_real(1:l_rows,1:l_cols_nev)
 #endif

src/elpa2/elpa2_template.X90

@@ -107,6 +107,7 @@
                                                                    &MATH_DATATYPE
     integer(kind=ik)                         :: na, nev, lda, ldq, nblk, matrixCols, &
                                                 mpi_comm_rows, mpi_comm_cols, mpi_comm_all
+    integer(kind=ik)                         :: eigenvalues_only
 
     call obj%timer%start("elpa_solve_evp_&
     &MATH_DATATYPE&
@@ -372,6 +373,12 @@
        stop 1
      endif
 
+     call obj%get("eigenvalues_only",eigenvalues_only)
+     if (eigenvalues_only .eq. 1) then
+       q(obj%local_nrows,obj%local_ncols) = 0.0
+       return
+     endif
+
 #if COMPLEXCASE == 1
      q(1:l_rows,1:l_cols_nev) = q_real(1:l_rows,1:l_cols_nev)