Toward a transferable parametrization for carbon in a periodic semi-empirical molecular orbital scheme

A new parametrization for carbon is proposed within the framework of the co mplete neglect of differential overlap molecular orbital theory in a scheme for systems with periodic boundary conditions using large-unit-cells and G amma point sampling, with an accurate treatment of the long-range Coulomb t ails of the interaction potentials. The new parametrization is obtained by fitting simultaneously experimental and theoretical data for electronic and structural properties of diamond and graphite. Remarkably, compared with o ther parametrizations existing in the literature and typically based on mol ecular data, it provides a better description of the relative stability bet ween the two phases, but it is still unsatisfactory in the description of t he elastic properties.