Consider this code:
units real
fix 1 all npt temp 500.0 300.0 100.0 iso 50.0 10.0 100.0
timestep 2.0
run 2000000
In this code, will pressurure and temperature be relaxed in the first 100 femto sectonds and then run for the next ~4 ns at the final temp and pressure? Or is the change gradual throught the entire run time?
Thanks!
The temperature is gradually ramped from Tstart and Tstop, same for pressure.
See fix nvt command — LAMMPS documentation for more details.
“The desired temperature at each timestep is a ramped value during the run from Tstart to Tstop . The Tdamp parameter is specified in time units and determines how rapidly the temperature is relaxed. For example, a value of 10.0 means to relax the temperature in a timespan of (roughly) 10 time units (e.g. τ or fs or ps - see the units command).”