How to calculate MAE from DFT result in meV/f.u. unit?|
- Date: 2023/09/06 20:55
- Name: Arifia Pratiwi N.
- References: https://www.openmx-square.org/openmx_man3.9/node114.html
- Dear all,
I have calculated the MAE using the second variational method, but I am confused about the units. I think I can convert the units from Hartree (the result from SCF) to eV using 1 Hartree = 27.2114 eV, but it doesn't match the example result (in meV/f.u.).
The formula I used is MAE = (E_90 - E_0) / S, where S = a^2 for cubic lattice. The already example as mentioned in the OpenMX 3.9 manual is FePt cubic system with lattice parameter a = 3.85 angstroms and MAE = 2.90 meV/f.u . There are four atoms (2 Fe and 2 Pt) in one lattice. Based on the formula, the MAE is 1.43553863e-05 Hartree = 3.90630158e-01 meV.
Is there anything missing in my unit conversion?