The memory requirements of VASP can easily exceed your computer facilities. In this case the first step is to estimate where the excessive memory requirements come from. There are two possibilities:
NKDIM*NBANDS*NRPLWV*16The factor 16 arises from the fact that all quantities are COMPLEX*16.
4*(NGXF/2+1)*NGYF*NGZF*16Once again all quantities are COMPLEX*16.
For a more accurate calculation of the memory requirements use the following sheet:
|MPLWM = NGXF*NGYF*NGZF/2 or|
|MPLWV = NGX *NGY *NGZ|
|minimal alloc (NEDOS=300)||4-10 Mbytes|
|arrays on large grid||( 5 + NTYP )*MPLWVM*16|
|arrays on small grid||3.5 *MPLWV *16|
|real space projectors||IRMAX*(LMDIM+2)*NIOND*8|
|rotation matrizes||3*NBANDS*NBANDS* IG|
|IG=16||for COMPLEX version|
|IG=8||for gamma point only version|
|IADD= 2||without residual minimization, 10 with residual minimization|
arrays on large grid:
CHTOT, DENCOR, CHTOTL, (CHGGA,CVTOT), CSTRF(NTYPD)
arrays on small grid
CHDEN, CV, CWORK3, CWORK4
CPTWFP, CPROJ, CPROTM
real space projectors
(..,..) means equivalence
In vasp.4.4 the memory requirements can be also calculated by the makeparam utility, which is supplied in the vasp.4.4 directory. It can be created by typing
> make makeparamin the vasp.4.4 directory.