[gmx-users] Problem with dihedral restraints

[gangotri dey]

Hello!

I posted a question a few days back and I got a reply but it still does not
work.

I have a small drug molecule that I would like to compute. I want to
restraint the Ramachandran dihedral angles. I have used the following lines
in the .itp file for the molecule. It was suggested that I increase the
force constant, which I did. However, I still see the change in the
dihedral angles after the NVT, NPT and Production run. I am not sure how
best it can be implemented.



[ dihedral_restraints ]
; ai   aj    ak    al  type  phi  dphi  kfac
698 702 692 691 1 -142.56 0 100
719 712 716 698 1 -84.24 0 100

702    698    716    712     1    50.3766     0 100
695    691    692    702     1  -166.8294     0 100


My .mdp file is similar to the one used in the Bevan lab tutorial online.




*Thank you*

*Gangotri Dey*