Example amber96
ONIOM(<Method>/<Basis Set>:AMBER=SoftFirst) geom=connectivity
<Title>
<Charge and Multiplicity> <Coordinates>
<Connectivity table>
<MM Parameter modifications>
With the "SoftFirst" option, the program will use the internally hardwired parameter file for AMBER and add the modifications given in the input file, with the latter taking preference over the internally hardwired parameters in case of duplicates.