Available up from VASP version 2.0.
The LOCPOT file contains the total local potential (in eV). To write this file, the line
LVTOT = .TRUE.must exist on the INCAR file (see section 6.49). In the present version (VASP.4.4.3), the electrostatic part of the potential only is written (exchange correlation is not added). This is desirable for the evaluation of the work-function, because the electrostatic potential converges more rapidly to the vacuum level than the total potential. However if the exchange correlation potential is to be included, change one line in main.F:
! comment out the following line to add exchange correlation
! INFO%LEXCHG=-1
CALL POTLOK(...)
Mind: Older version might have had a different behavior, when they
were retrieved from the server. Please always check
yourself, whether main.F is working in the way you expect
(simply search for LEXCHG=-1 in main.F).
If the line LEXCHG=-1 is commented out, the exchange
correlation is added.
It is recommended to avoid wrap around errors, when evaluating LOCPOT.
This can be done by specifying PREC=High in the INCAR file.
The data arrangement on the LOCPOT file is similar to that of the CHGCAR file (see section 5.10).