Order-Nmethod for a nonorthogonal tight-binding Hamiltonian

Abstract
We have developed an order-N method to calculate the total energy and atomic forces for a nonorthogonal tight-binding Hamiltonian. We have first confirmed the validity of our approach by comparing our results with the exact calculation for a small silicon cluster. The efficiency of our approach for a large system is demonstrated by determining the equilibrium configuration of a Si1000 cluster using quenching and annealing techniques based on molecular dynamics.