GROMACS version: 2020
GROMACS modification: No
I am trying to simulate a protein-protein complex using Martini force field. The complex dissociates in the absence of any restraints. So, I am trying to impose distance restraints on the interface residues.
I wrote the following .itp file
; distance restraints for adam-vdw
[ intermolecular_interactions ]
[ distance_restraints ]
; ai aj type index type’ low up1 up2 fac
248 1335 1 0 1 0.0 0.3 0.4 1.0
The atom numbers are global.
I then included this file in the topology file as follows
[ system ]
Insanely solvated protein.
[ molecules ]
; name number
When I use this way to set up the simulation, I get the following error
Syntax error - File A-B-dist.itp, line 2
Last line read:
‘[ intermolecular_interactions ]’
Invalid order for directive intermolecular_interactions
Could someone please help me in understanding the proper order or what else I am doing wrong here?
I would be grateful for any suggestions.