while testing my code I came across a potential problem concerning volume factors in the outcome of the application of an operator created by 'create_power_operator'
minimal example to show differences between Nifty_1 and Nifty_3
Since 'res_1!= res_2', either Nifty_1 or Nifty_3 calculates something wrong.
In my mind Nifty_1 does the calculation properly. An easy fix in Nifty_3 create_power_operator could be setting the bare keyword in line 43 of the DiagonalOperator to true.