The pseudopotential generation package is not distributed with VASP for three reasons. (i) The package is not particularly user friendly: we had too many queries how to use it, and why some features did not work the way the users expected. (ii) Second, it is our aim to generate a consistent thoroughly tested data base for all elements in the periodic table. Centralising the pseudopotential generation, allows us to build up this basis more efficiently. Most users will certainly profit from this strategy. (iii) Finally and admittedly, we want to protect our know-how and data base. Pseudopotential generation is still largely a kind of black art, and despite being not particularly user friendly, the current pseudopotential generation code is among the most powerful one available.
The pseudopotential generation package consists of two separate programs. The first one is called
rhfspsand generates the l dependent pseudopotentials, the second one called
fourpot3prepares the pseudopotentials for VAMP and creates the POTCAR file, which can be used by VAMP. Several files are used by both programs:
PSCTR V_RHFIN V_RHFOUT V_TABIN V_TABOUT PSEUDO WAVE_FUNCTION DDE POTCARThe central input file for both programs is PSCTR. It contains all information for the calculation of the pseudopotential. The input file V_RHFIN on the other hand describes the atomic reference configuration and controls the all electron (AE) part of the pseudopotential generation program. The pseudopotential generation program rhfsps creates the files PSEUDO and WAVE_FUNCTION, which are read and interpreted by the fourpot3 program. The final output file is the POTCAR file, which can be read by VAMP.
Mind: All programs discussed in this section use a.u., energies are always in Rydberg. This is an important difference to VAMP (which uses eV and ).