Muffin-tin orbitals and molecular calculations: General formalism

摘要: An account is given of a new formalism for calculating energy levels in molecules using techniques that derive from the band theory metals. After showing how molecular potential may be transformed into cellular we define basis set muffin-tin orbitals and discuss some their properties. The relationship between scattered wave formulation Johnson, which restricted to potentials, our more general approach based on use linear combination (L.C.M.T.O.) explicitly indicated. We then show properties orbitals, together with technique integration, give rise hamiltonian matrix. This matrix as as, but simpler than obtained by atomic it therefore computationally faster secular method.