How to maintain and equilibrate system at room condition in boundary S P P

Dear all

I want to do indent in a cubical system compose of cu atoms along x-axis. For that, I want to maintain and equilibrate system at room condition i.e.300 k and 1 atm in boundary S P P.

How it is possible in lammps. Because only NVE ensemble seems to be work in this boundary condition.

thanks

Dear all

I want to do indent in a cubical system compose of cu atoms along x-axis.
For that, I want to maintain and equilibrate system at room condition
i.e.300 k and 1 atm in boundary S P P.

How it is possible in lammps. Because only NVE ensemble seems to be work in
this boundary condition.

that is an incorrect statement for two reasons.

1) the NVE ensemble is only defined for a fully periodic system where
no other manipulations of the sysstem is done outside of time
integration. you can use fix nve in a system with a non-periodic
boundary, you won't sample an NVE ensemble in this case.

2) you can very well thermalize your system with either nose-hoover
thermostat fixes, which maintain temperature and do time integration
or with fix nve in combination with one of the many thermostat fixes
(langevin, temp/berendsen, temp/csvr, temp/csld, gle, gld, ...).
however, you cannot really "control' pressure with free surfaces. the
system will relax into what is consistent with the potential and
kinetic energy in the system. that said, you can use any kind of
thermostat that LAMMPS offers for such a system, if you set it up
correctly.

axel.