Mapping VASP energy components to fundamental energy terms.
Dear VASP experts,
I am working on understanding the detailed energy decomposition in VASP calculations. Specifically, I'm trying to map the VASP output energy terms to the fundamental energy components in the form:
E_total = E_k + E_e-i + E_e-e + E_xc + E_ii
where:
E_k is the electron kinetic energy
E_e-i is the electron-ion Coulomb interaction energy
E_e-e is the electron-electron Coulomb interaction energy
E_xc is the exchange-correlation energy
E_ii is the ion-ion Coulomb interaction energy
From my VASP calculation, I get the following output:
Code: Select all
Free energy of the ion-electron system (eV)
---------------------------------------------------
alpha Z PSCENC = 5940.78324452
Ewald energy TEWEN = -76597.15246038
-Hartree energ DENC = -25624.22804859
-exchange EXHF = 0.00000000
-V(xc)+E(xc) XCENC = 5331.25611792
PAW double counting = 130768.62475327 -135400.57600830
entropy T*S EENTRO = 0.00000000
eigenvalues EBANDS = -5517.65706306
atomic energy EATOM = 99205.15615738
Solvation Ediel_sol = 0.00000000
---------------------------------------------------
free energy TOTEN = -1893.79330725 eV
My questions are:
1. How do these VASP output terms map to the fundamental energy components listed above? For example, does TEWEN directly correspond to E_ii, or are there additional corrections needed?
2. How should the PAW double counting terms and atomic energy be distributed among these components?
3. Is there any published reference that explicitly shows this mapping between VASP output terms and fundamental energy components?
I understand that in practice we usually work with energy differences rather than absolute values, but I'm interested in understanding how these individual components contribute to the total energy from a theoretical perspective.
Thank you very much for your help and guidance.
Best regards,
Zhao