[gmx-users] force field

[hhhh huan]

Dear all gmx users and developers,

I am running a simulation of esters. However,i failed to allocate the force field of 1 of the Carbons. (I am using OPLS-AA force field)

-C-C=C-C-C=C-C-
       *

The Carbon atom labeled with symbol * cannot be identified. I checked the ffoplsaa.atp file but I cant find the suitable one.

I wish that someone can help me to solve the problems.
Any suggestions and helps are appreciated.

Thanks