[gmx-users] Two [ defaults ] sections

[Alexander Alexander]

Dear gromacs user,

I have a system containing a "peptide+water+solid surface", for the
"peptide+water" I hired the OPLS-AA force field which has below [ defaults
] section in its "oplsaa.ff/forcefield.itp"

[ defaults ]
; nbfunc        comb-rule       gen-pairs       fudgeLJ fudgeQQ
       1                3                    yes                0.5
0.5

While I would like to specify the below [ defaults ] section in for the
solid surface.

[ defaults ]
;  nbfunc        comb-rule       gen-pairs       fudgeLJ fudgeQQ
       1                 3                    no                0.5
0.5

Here the only different between the two [ defaults ] section is just
"gen-pairs" (that I do not know how big would be the side effect if I just
used the one for OPLS-AA force for the whole new system containing solid
surface as well?!)

But in general, I would be highly appreciated if you let me know how I can
have two different [ defaults ] sections in my final "peptide+water+solid
surface" system.

Many thanks.

Cheers,
Alex