Abstract
We present new algorithm for density functional theory to avoid charge sloshing problems. In metallic electron structure calculation of large scale, such as Si-Al or Ga-As interface, the numerical instability called charge sloshing occurs during the self-consistent iterations due to its strong coupling between Poisson and Kohn-Sham equations. In traditional algorithm two equations are solved succesively, and potentials or electron densities obtained from present and previous iterations were mixed in some procedure using appropriate parameters for each system. This procedure, however, is not so efficient for the large electron structure calculations which require computational time of 2-3 monthes until the calculation is done. So we proposed a strong coupled formalism of two equation based on the mixed variational principle. In our algorithm Poisson equation and Kohn-Sham equation are solved simultaneously without any parameters.
