Penalty energy for constrained magnetism calculations

[sophie_weber]

Hello,

I am currently performing a constrained magnetic calculation where the energy differences between different magnetic directions are very small, closer to the order of the penalty energy. So when assessing the lowest energy configuration I need to be careful to ensure the penalty energy is smaller than the energy difference. I wanted to confirm if E_p as recorded in the OSZICAR file is for the total unit cell, or is it the average value per atom (i.e., can I compare the E_p and TOTEN values directly, or do I need to divide TOTEN by the number of atoms in the unit cell?)

Thank you,
Sophie

[henrique_miranda]

Hi Sophie,

E_p is for the total unit cell and you can compare it with TOTEN directly.
It is computed as the sum of the penalty energy for all the ions in the system.

[sophie_weber]

Great! Thank you so much for the clarification, I appreciate it!