The atom charges are in the topology files (.rtf), and L-J values are in the parameter files (.prm). The L-J epsilon values are in kcal/mol; instead of sigma, Rmin/2 values are used.

I am not certain that there is an H2SO4 residue in the force field, although there are sulfates as pendant groups, and also CH3SO4- anion.

Rick Venable
computational chemist