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6.1 makeparam utility

 

The makeparam utility generates automatically the param.inc file (an include file that is required in the f77 version). Mind: the utility makeparam is no longer required in VASP.4.X, but to learn something about the default setting for NGX, NGXF etc. read this section. In vasp.4.4 the makeparam can be used to estimate the memory requirements of the code.

The program is started by typing

> 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.

The values for NGX,Y,Z are controlled by the PREC-tag in the INCAR file. Possible values for PREC are

displaymath4355

For PREC=High wrap around errors are avoided (see section 9.2). For PREC= Low or Medium the 3/4 rule is used (see section 10.4), i.e. NGX,Y,Z is set to 3/4 of the value, which avoids wrap around errors. (The main difference between PREC=Low and PREC=Med is the determination of the default energy cutoff ENCUT 7.7). The values for NGXG, NGYF and NGZF are determined from the necessary cut-off for the augmentation charge ENAUG (see section 7.6).

To summarize: Three flags in the INCAR file control the makeparam utility:


next up previous contents
Next: 6.2 NGXY,Z and NG(X,Y,Z)F Up: 6 The param.inc file Previous: 6 The param.inc file

MASTER USER VASP
Mon Mar 29 10:38:29 MEST 1999