[lammps-users] NVT pressure calculation

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1

I am running simulation of a tension test. I apply strain by displace_box in one direction and then i equilibrate the sytem by fix nvt and i fix the pressure by fix press/berendsen. now i use thermo to get the pressure vector. Then for each strain increment i average all the stress and the displacement to get just one value for stress and one for strain. I have two question, first can we use this equilibration in strain load test, and second the pressure that i get from thermo , is it equal to Cijkl*ekl meaning if i plot stress vs strain, do i get the correct elastic modulus.

thanks

2

If you are trying to use fix nvt while applying a strain, it may not
work well, since you may be putting a lot of energy into the system.
Nose/Hoover can have problems and oscillate when that happens.
You'll just have to try it and play with the damping constant and other
options to see what happens.
Re:elastic modulus - the doc page for the pressure tensor is clear
about what it is calculating - you'll have to decide if that is what you
want.

Steve