Molecular Dynamics (MD)

[NW]

Dear ATK experts,

I want to run MD and increase the temperature during the simulation from 300K to 1000K. Is it a good way to use NVT ensemble? and select 300K in initial velocity section and 1000K for reservoir and final  temperatures?
Because as far as I know in the NVT  ensemble the number of particles, the volume and the temperature are fixed.

[Ulrik G. Vej-Hansen]

Yes, NVT means that the temperature is the controlled value, so it can still be changed to simulate heating. The reservoir temperature is the initial reservoir temperature, so it should be 300 K in your example here. Please see our tutorials on Molecular Dynamics, including this one which might be of interest: https://docs.quantumwise.com/tutorials/diffusion_liquid_copper/diffusion_liquid_copper.html

[NW]

Many thanks for your help.
I am not sure which type of ensembles is proper in this case for solid structure. NVT or NPT?

[Ulrik G. Vej-Hansen]

That depends on your physical model. In most cases, an initial equilibration with NPT is a good idea, but it is really a scientific/modelling choice, not software. Please consult our tutorial on MD basics: https://docs.quantumwise.com/tutorials/md_basics/md_basics.html