A Robust Spectrum Slicing Method Applied to the Kohn-Sham Equation for the Liquid/Solid Silicon Interface

A difficult aspect of solving the Kohn Sham equation is the super-linear scaling of eigensolvers with the number of valence orbitals desired. We present a robust spectrum slicing technique that calculates the valence orbitals in a divide and conquer fashion through the use of smooth Chebyshev-Jackson filters. This algorithm allows for a ``parallel'' implementation of the eigensolver. Our calculations are done in the real-space density functional framework implemented in the program PARSEC. We apply this method to examine the liquid-solid silicon interface.