Fusion of the LAPW and LMTO methods: The augmented plane wave plus muffin-tin orbital method

We present a full potential linearized method to solve the one-body problem, for example in the local density approximation. A mixed basis of augmented plane waves and generalized muffin-tin orbitals (MTOs) are used for the eigenfunctions. Since MTOs efficiently describe low-energy and localized states, the mixed basis is dramatically more efficient than the linearized augmented plane wave method for a given tolerance. GaAs, MnAs, SrTiO(3), Cu, and the O(2) dimer are used as illustrations.