Development and Considerations for Practical Application of the Electronic Structure Calculation Method Using the Imaginary Time Evolution Method

Abstract

In this paper, we propose an imaginary-time evolution method to obtain self-consistent static electronic states according to real-time TDDFT calculations. This method provides very good convergence accuracy and stability concerning the ground state, as well as a large number of computational steps due to obtaining all states to evolve simultaneously. Also, we can get a diffusion equation from this method as the same as the real-time TDDFT and can probably unify these time-evolution calculations in the same framework which is used in electronic structure calculations. In this study, we show that this method is effective in practical electronic state calculations. We will show several improvements and calculations with the computational process using the imaginary time evolution method in combination with the conventional DFT algorithm for practical use. The results of calculations of systems such as hydrogen atoms, hydrogen molecules, and ethylene can show the computational efficiency and accuracy of this method, which probably improves traditional self-consistent electronic structure calculations for practical systems.