Hello,
I need to create rigid dumbbells that are confined in two dimensions. I saw that there are different ways to do it, and opted for rattle algorithm.
As I need both to thermalize the system and set the force on z equals to zero, I used these fixes in sequence:
fix 1 all nve
fix 2 all langevin 0.05 0.05 0.1 7456
fix 3 all setforce NULL NULL 0.0
fix 4 all rattle 0.0001 20 100 b 1
My question is if I can apply a langevin thermostat to each particle after the velocity verlet integration (nullifying the force on z), and then constrain the two particles of a dumbbell to a definite length.
Would the system thermalize in this way correctly only the translational degrees of freedom for the center of mass and the rotational one?
I know I could do the same with
fix 1 all rigid/small molecule langevin 0.1 0.1 0.1 7456
fix 2 all enforce2d
but I need the first version for other issues and also because I think is a little bit faster using the rattle algorithm.
Thanks in advance!
Antonio