2.2 Outline of the structure of the program

 

VASP.3.X is a F77 program, and VASP.4.X a F90 code. Generally the outline for the directories will be as follows:

src/vasp.lib
src/vasp.3.2
src/vasp.4.lib
src/vasp.4.2
pot/..
pot_GGA/..
workdir/param.inc
         INCAR  POTCAR  POSCAR   KPOINTS

vasp.lib (vasp.4.lib) contains code which rarely changes, and requires usually no re-installation between updates, but might require adaption for new computer platforms. vasp.3.2 (vasp.4.2) contains the main F77/F90 code. Pseudopotentials are now available on a file server (see section 3.2). and should be installed locally for instance in the pot/ directory (see section 12).

To work with the code a work directory is usually used. For an actual calculation several files will be required in the work directory. Usually these files are

 INCAR  POTCAR  POSCAR   KPOINTS
 param.inc (VASP.3.X only)

The param.inc is ``included'' during compilation of the main.F file of VASP.3.X and contains information about the maximum size of the system -- for instance (see section 6), maximum number of ions
maximum number of plane wave
maximum number of k-points

A utility for creating the param.inc file automatically was added in version VASP.3.2. The name of the utility is

> makeparam

and it prompts an appropriated param.inc file to the screen. Before running the makeparam utility all other input files (INCAR, POSCAR, POTCAR and KPOINTS) must exist in the current work directory (for details see section 6). The makeparam utility is located in the vasp.3.X directory and must be compiled separately by typing

> make makeparam

in the vasp.3.X directory. To recompile the VASP.3.X code you might use the batch file getvasp (in the vasp.3.X directory), which copies the param.inc from the current directory to the vasp.3.X directory, compiles the code there and copies finally a working version of vasp back to the local directory. (Usually it is necessary to customize the getvasp batch file.)

We recommend to make the makeparam and getvasp utilities available somewhere in your search path. Do this now before starting with the tutorial. If you have not installed vasp please read the section 3.2 now.