Abstract: | To obtain convergent numerical approximations without using any orthogonalization operations is of great importance in electronic structure calculations. In this paper, we propose and analyze a class of iteration schemes for thediscretized Kohn-Sham Density Functional Theory model, with which the iterativeapproximations are guaranteed to converge to the Kohn-Sham orbitals without anyorthogonalization as long as the initial orbitals are orthogonal and the time stepsizes are given properly. In addition, we present a feasible and efficient approach toget suitable time step sizes and report some numerical experiments to validate ourtheory. |