Is there constraint forces contribute in what I am saving in the .trr format?

GROMACS version: 2020
GROMACS modification: No

Hi everyone,
When I use some holonomic constraints on my atoms (eg. SHAKE or LINCS), the total force is given by the gradient of the potential-energy plus a contribute of constraint forces fixed by lagrangian multipliers and the expression of the constraint. When I am saving forces for each single atom in the mdp option, am I saving the total force or only one of these contributes?

Thanks for the help.


The forces saved in the trr file contain only the gradient of the potential, no constraint contributions.