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 the discretized Kohn-Sham Density Functional Theory model, with which the iterative approximations are guaranteed to converge to the Kohn-Sham orbitals exponentially without any orthogonalization as long as the initial orbitals are orthogonal and the time step sizes are given properly. In addition, we present a feasible and efficient approach to get suitable time step sizes.

翻译：在电子结构计算中,为了在不使用任何正对角化操作的情况下获得趋同数字近似值,我们建议和分析离散的Kohn-Sham密度功能理论模型的迭代办法,保证迭代近似值与Kohn-Sham轨道模型成倍地趋近,而没有任何正对角化,只要最初的轨道是正对角的,并且适当给出了时间步骤大小。此外,我们提出了一个可行和有效的办法,以获得适当的时间步骤大小。