Related Experiment Video
Updated: Feb 3, 2026

Picometer-Precision Atomic Position Tracking through Electron Microscopy
Published on: July 3, 2021
Momentum-resolved TDDFT algorithm in atomic basis for real time tracking of electronic excitation
Chao Lian1, Shi-Qi Hu1, Meng-Xue Guan1
1Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
Abstract:
Ultrafast electronic dynamics in solids lies at the core of modern condensed matter and materials physics. To build up a practical ab initio method for studying solids under photoexcitation, we develop a momentum-resolved real-time time dependent density functional theory (rt-TDDFT) algorithm using numerical atomic basis, together with the implementation of both the length and vector gauge of the electromagnetic field. When applied to simulate elementary excitations in two-dimensional materials such as graphene, different excitation modes, only distinguishable in momentum space, are observed. The momentum-resolved rt-TDDFT is important and computationally efficient for the study of ultrafast dynamics in extended systems.
Related Concept Videos
Atomic Orbitals
Electron Configuration of Multielectron Atoms
Electronic Structure of Atoms
An atom comprises protons and neutrons, which are contained inside the dense, central core called the nucleus, with electrons present around the nucleus. Taking into account the wave–particle duality of electrons and the uncertainty in position around the nucleus, quantum mechanics provides a more accurate model for the atomic structure. It describes atomic orbitals as the regions around the nucleus where electrons of discrete energy exist, characterized by four quantum...
Atomic Structure
Hybridization of Atomic Orbitals I
The Energies of Atomic Orbitals

