From VASP Wiki

CSVR_PERIOD = [real]
Default: CSVR_PERIOD = 0 

Description: Time scale of the CSVR thermostat in terms of the number of MD steps.

CSVR_PERIOD sets the time scale () of the CSVR thermostat. It is expressed in terms of the number of MD steps and must be interpreted in combination with the time step set by POTIM. Typically, CSVR_PERIOD should take the values corresponding to 2-2000 fs, whereby the smaller the value, the more aggressive the thermostating. The special setting CSVR_PERIOD=0 generates the NVE ensemble.

Related tags and articles

POTIM, CSVR thermostat