IWAVPR-tag

$$IWAVPR = 0 \vert 1 \vert 2 \vert 3$$

Default
if IBRION=0 (MD)	2
if IBRION=1,2 (relaxation)	1
else (static calculation)	0

IWAVPR determines how wave functions and/or charge density are extrapolated from one ionic configuration to the next configuration. Usually the file TMPCAR is used to store old wavefunctions, which are required for the prediction. If IWAVPR is larger than 10, the prediction is done without an external file TMPCAR (i.e. all required arrays are stored in main memory, this option works from version VASP.4.1). If the IWAVPR is set to 10, the reader will set it to the following default values:

if IBRION=0 (MD)	12
if IBRION=1,2 (relaxation)	11

0

no extrapolation, usually less preferable if you want to do an ab initio MD or an relaxation of the ions into the instantaneous groundstate.

1,11

Simple extrapolation of charge density using atomic charge densities is done (eq. (9.8) in thesis G. Kresse). This switch is convenient for all kind of geometry optimizations (ionic relaxation and volume/cell shape with conjugate gradient or Quasi-Newton methods, i.e. IBRION=1,2)

2,12

A second order extrapolation for the wave functions and the charge density is done (equation 9.9 in thesis G. Kresse). A must for ab-initio MD-runs.

3,13

In this case a second order extrapolation for the wave functions, and a simple extrapolation of charge density using atomic charge densities is done. This is some kind of mixture between IWAVPR=1 and 2, but it is definitely not better than IWAVPR=2.

Mind: We don't encourage this setting at all.