This thesis details the techniques used in constructing a library of improved parameters for the Tersoff bond-order potential energy model which is used in atomistic modelling applications. The parameters presented here are for the elemental type-IV diamond structure semiconductors and the binary III-As, III-P, III-Sb and the cubic III-N compound semiconductors. The parameters are fitted to a number of experimental and DFT predicted properties of the materials including the lattice parameter, the cohesive energy, the elastic constants and the lattice dynamical properties, including phonon frequency and mode-Gruneisen parameters, for three pertinent locations in the Brillouin zone.