Ex) Article Title, Author, Keywords
New Phys.: Sae Mulli 2020; 70: 646-651
Published online August 31, 2020 https://doi.org/10.3938/NPSM.70.646
Copyright © New Physics: Sae Mulli.
1Department of Physics, Chungbuk National University, Cheongju 28644, Korea
The excited state dynamics of electrons in materials is crucial for understanding various phenomena in nature and applications. However, time-dependent density functional theory, which is a first-principles method for studying electronic dynamics, requires extensive computational power, which makes theoretical study difficult. In this work, we studied how to improve the computational speed of TDDFT. A Crank-Nicolson approximation for a time evolution operator of the time-dependent Kohn-Sham equation preserves unitarity and preforms a high-speed calculation in a localized atomic orbital basis. By including a self-consistent loop in the Crank-Nicolson approximation, we were able to increase the calculational speed by more than tenfold while maintaining the calculational accuracy and stability. In this way, we made possible the application of the first-principles method to the study of excited state dynamics on a long time scale.
Keywords: TDDFT, Excited state dynamics, Method