Dear all,
I have one puzzling question. I thought, generally, if we change the potential coefficients among rigid body’s atoms themselves and keep other the potential coefficients the same , the result shouldn’t be different, because it’s rigid, right?
However, my simulation result told me it’s different. Why?
Here is my part of code. I just change the sigma and epsilon in pair_coeff 5 5 1.0 1.0 2.5 , others are the same. And all atom 5 forms one particle.
pair_style lj/cut 2.5
pair_coeff * * 1.0 1.0 2.5
pair_coeff 1 2 1.0 1.0 1.12246
pair_coeff 2 3 1.0 1.0 1.12246
pair_coeff 1 4 1.0 1.0 1.12246
pair_coeff 3 4 1.0 1.0 1.12246
pair_coeff 5 5 1.0 1.0 2.5
…
group dimers type 3 4
group no_dimers subtract all dimers
group particles type 5
…
fix nvtnR no_dimers nvt temp ${Tstar} ${Tstar} $(v_dt*10)
fix nvtR dimers rigid/nvt/small molecule temp ${Tstar} ${Tstar} $(v_dt*10)
fix nvtP particles rigid/nvt molecule temp ${Tstar} ${Tstar} $(v_dt*10)
fix P all press/berendsen iso ${press} ${press} $(v_dt50001000) dilate all
I also have one idea that even if I didn’t change other potential parameters, I do change the particle(atom 5) potential energy, so the difference of particles influence total system?
Thanks very much!