[gmx-users] Excluding coulomb interactions only

[Walter Ash]

What is the behavior of gromacs if you are excluding 1-4 interactions, 
but have pairs of atoms with L-J parameters listed under [ pairtypes ]?  
Is it possible to exclude only 1-4 coulomb interactions while 
maintaining interactions defined in [ pairtypes ]?  Also, does the LJ 
fudge factor (e.g. the OPLS-AA 0.5 factor) get applied to the 
interaction parameters listed in [ pairtypes ] or is this factor only 
used when regular LJ parameters from [ atomtypes ] are used (with 
combination rules, if needed)?

I've seen some stuff in the archives but I couldn't find anything very 
certain.