[gmx-users] combination rules -- the part about the combination rules

[chris.neale at utoronto.ca]

For LJ interactions, use [ pairtypes ]. For Coulombics there is  
unfortunately no analogous solution. I am not clear about exactly what  
you want to do. What "parameters" are you interested in, or by this do  
you just mean LJ and Q?

Chris.

-- original message --

Hello,
     I was wondering how to set up parameters for interactions between  
two different atoms A and B. Since for Gromacs parameters are defined  
to each kind of atom, I cannot specify parameters between A and B. For  
Buckingham potential, the rule was:
    A_ij=(A_ii * A_jj)^(1/2)
So anyone know how to specify this value while not using the  
combination rules?
--snip--