  Methodologies for creating reactive potential energy surfaces from molecular
mechanics force-fields are becoming increasingly popular. To date, molecular
mechanics force-fields use harmonic expressions to treat bonding stretches,
which is a poor approximation in reactive molecular dynamics simulations since
bonds are displaced significantly from their equilibrium positions. For such
applications there is need for a better treatment of anharmonicity. In this
contribution Morse bonding potentials have been extensively parameterised for
the atom types in the MM3 force field of Allinger and co-workers using high
level CCSD(T)(F12*) energies. To our knowledge this is the first instance of a
large-scale paramerization of Morse potentials in a popular force field.
