NHC_PERIOD

NHC_NCHAINS = [real]
Default: NHC_NCHAINS = 40 

The only parameter of the Nose-Hoover chains thermostat NHC_thermostat is the time scale ($\tau$) of the system. This parameter, expressed in terms of the number of MD steps, is defined using the flag NHC_PERIOD. Typically, NHC_PERIOD should be set to a value between 40 and 200.