[gmx-users] Short question about 1-4, 1-5+ interactions

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Dear all,

I have a question about internal bond interactions within a molecule.

I understand that 1-4 interactions can be scaled with "nbfunc". But I wonder:

1. What is the default for 1-5 and larger interactions in Gromacs? Are the LJ and charge interactions included (i.e., not scaled)? I'm specifically interested in reproducing OPLS United-Atom molecules from Jorgensen's 1986 OPLS paper. He doesn't mention anything about scaling in that paper though so I guess he's not doing any scaling of any inner-molecule interactions at all (please someone correct me if this is obviously wrong).

2. Is there any way to scale the 1-5+ interactions in Gromacs?

Thanks in advance! I appreciate any help.

Tom