Full-potential screened spherical wave based muffin-tin orbital method for density functional theory

We report a full-potential (FP) screened spherical wave based tight-binding muffin-tin orbital (TB-MTO) method to implement the all-electron density functional theory (DFT). In this work, to realize accurate calculation of the full charge density, full potential, Hamiltonian, and total energy, a double augmentation scheme is introduced to represent the basis TB-MTO. To demonstrate the high accuracy of the FP-TB-MTO method, we apply it to compute the total energy and extract the equilibrium lattice constants, phase ordering, and elastic constants for bulk Co, Ni, and Fe, and our results match very well with another well-established FP method. The FP-TB-MTO-based DFT provides an accurate first-principles tight-binding electronic structure method for material simulations.