[gmx-users] dihedral restraint

[gangotri dey]

Hello all,

I am a relatively new user of gromacs. Hence, I am encountering some
problem.

I am studying few drug molecules onto a metal oxide surface. I would like
to constrain the Ramachandran angles. I am using gromacs version 5.4.0.

I have added the dihedral restraint angles in the itp file that reads as
follows.

[ dihedral_restraints ]
; ai   aj    ak    al  type  phi  dphi  kfac
698 702 692 691 1 163.19 0 1
719 712 716 698 1 -84.24 0 1

712 716 698 689 1 -35.93 0 1
702 692 691 686 1 180.42 0 1

I have read in this forum that there is no need to add any more key words
like the previous version in the mdp file.


However, the dihedral angles are changing and I am not sure how to restrain
them.
Is there any part that I am missing.


*Thank you*

*Gangotri Dey*