EMBEDDING MUFFIN-TINS INTO A FINITE-DIFFERENCE GRID

A new method is given for calculating the electronic structure of soli ds, enabling finite-difference methods to be used for systems with dee p atomic potentials. In muffin-tin spheres around the nuclei, the atom ic wave functions are determined using standard numerical techniques. They are then matched onto a finite-difference grid in the interstitia l region by an embedding procedure by which the interior of a muffin-t in is replaced by an embedding potential at its boundary. The sparse H amiltonian matrix of the grid can be diagonalized using methods with t ime sealing linear with the system size. We present results for f.c.c. copper.