My Community

Dear vasp-community,

the different energy contributions to the total energy (TOTEN) are printed in the OUTCAR to a table denoted as "Free energy of the ion-electron system (eV)". The meaning of these contributions has been discussed elsewhere. I would like to know how these values are combined to actually yield the total energy. Summing up Ewald, alpha-z, eigenvalues and subtracting double-counting corrections and the atomic energy does not give the value that is printed below.

So in which way are the energy contributions combined to give the total energy?

Here is an example of bulk MgO:

Free energy of the ion-electron system (eV)
---------------------------------------------------
alpha Z PSCENC = 269.62822626
Ewald energy TEWEN = -3810.46122208
-Hartree energ DENC = -1241.26456125
-exchange EXHF = 0.00000000
-V(xc)+E(xc) XCENC = 224.80200700
PAW double counting = 4352.69155602 -4830.96985278
entropy T*S EENTRO = -0.00000000
eigenvalues EBANDS = -968.12453927
atomic energy EATOM = 5956.22451900
Solvation Ediel_sol = 0.00000000
---------------------------------------------------
free energy TOTEN = -47.47386709 eV

energy without entropy = -47.47386709 energy(sigma->0) = -47.47386709

Thanks.

Just sum all the numbers.

EBANDS+DENC+XCENC+TEWEN+PSCENC+EENTRO+PAW double counting+EATOM+EXHF+Ediel_sol = TOTEN
269.6282263 -3810.461222 -1241.264561 + 0 + 224.802007 -4830.969853 + 4352.691556 + 0 -968.1245393 + 5956.224519 = -47.4738671

Okay thanks.