5.2 Purpose of the Various Hydrogen Bond Variables.

     Variable  Default      Function
     
     DUMMy                  Sets CUTHB and CUTHBA to zero. This will result
                            in no hydrogen bonds which is desirable when one
                            is not interested in the hydrogen bond energy.
                            The selection will be done very quickly in this
                            case.
     
     CUTHB     4.5          Maximum distance allowed for a hydrogen bond. This
                            distance is measured between the heavy atoms
     
     CTOFHB    CUTHB-0.5    Distance where distance switching function is off
                            Once specified, it will only change if respecified.
     
     CTONHB    CTOFHB-0.5   Distance where distance switching function is on.
                            Once specified, it will only change if respecified.
     
     CUTHBA    90.0         Maximum out of line angle allowed for a three
                            atom hydrogen bond. The angle is 180 - D--H...A angle.
                            If this value is less than or equal to 0,
                            then all possible angles will be allowed.
     
     CTOFHA    CUTHBA-20.0  Angle where angle switching function is off
                            Once specified, it will only change if respecified.
     
     CTONHA    CTOFHA-20.0  Angle where angle switching function is on.
                            Once specified, it will only change if respecified.