def checkCoulombPair(parameters, group1, group2, distance):
    """
    Checks if this Coulomb interaction should be done - a propka2.0 hack
    """
    Npair = group1.Nmass + group2.Nmass
    do_coulomb = True
    if not (group1.titratable and group2.titratable):
        do_coulomb = False
    if distance > parameters.coulomb_cutoff2:
        do_coulomb = False
    if Npair < parameters.Nmin:
        do_coulomb = False
    return do_coulomb
