forces on atoms with rigid model

Dear all,

I am generating a water trajectory with rigid water model. To do this, I need to add a constraint with fix shake so that the bond and angles can be kept rigid. Now I want to dump forces on atoms without contribution of constraint forces. I tried to put fix store/force before all other fixes but no difference was produced. Anyone could help? Thx!

Dear all,

I am generating a water trajectory with rigid water model. To do this, I
need to add a constraint with fix shake so that the bond and angles can
be kept rigid. Now I want to dump forces on atoms without contribution
of constraint forces. I tried to put fix store/force before all other
fixes but no difference was produced. Anyone could help? Thx!

you could use the “rerun” command on a previously recorded trajectory. since you are using a pre-recorded trajectory, you don’t need to specify fix shake and can compute and dump all force components including intra-molecular ones.

axel.

Fix store/force should do what you want. How did you output
the dump file? You would need to access the values
that fix store/force is storing.

Steve