# Velocity-gauge real-time TDDFT within a numerical atomic orbital basis set

## Abstract

The interaction of laser fields with solid-state systems can be modeled efficiently within the velocity-gauge formalism of real-time time dependent density functional theory (RT-TDDFT). In this article, we discuss the implementation of the velocity-gauge RT-TDDFT equations for electron dynamics within a linear combination of atomic orbitals (LCAO) basis set framework. Numerical results obtained from our LCAO implementation, for the electronic response of periodic systems to both weak and intense laser fields, are compared to those obtained from established real-space grid and Full-Potential Linearized Augmented Planewave approaches. As a result, potential applications of the LCAO based scheme in the context of extreme ultra-violet and soft X-ray spectroscopies involving core-electronic excitations are discussed.

- Authors:

- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Univ. of Washington, Seattle, WA (United States)
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg (Germany)
- Univ. of Tsukuba, Tsukuba (Japan)
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

- Publication Date:

- Research Org.:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)

- Sponsoring Org.:
- USDOE

- OSTI Identifier:
- 1434676

- Grant/Contract Number:
- AC02-76SF00515; AC02-05CH11231; FG02-ER45623; 15H03674; JPMJCR16N5

- Resource Type:
- Journal Article: Accepted Manuscript

- Journal Name:
- Computer Physics Communications

- Additional Journal Information:
- Journal Volume: 226; Journal Issue: C; Journal ID: ISSN 0010-4655

- Publisher:
- Elsevier

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 74 ATOMIC AND MOLECULAR PHYSICS; Real-time TDDFT; Electron dynamics; X-ray spectroscopy; Core-level spectroscopy

### Citation Formats

```
Pemmaraju, C. D., Vila, F. D., Kas, J. J., Sato, S. A., Rehr, J. J., Yabana, K., and Prendergast, David.
```*Velocity-gauge real-time TDDFT within a numerical atomic orbital basis set*. United States: N. p., 2018.
Web. doi:10.1016/j.cpc.2018.01.013.

```
Pemmaraju, C. D., Vila, F. D., Kas, J. J., Sato, S. A., Rehr, J. J., Yabana, K., & Prendergast, David.
```*Velocity-gauge real-time TDDFT within a numerical atomic orbital basis set*. United States. doi:10.1016/j.cpc.2018.01.013.

```
Pemmaraju, C. D., Vila, F. D., Kas, J. J., Sato, S. A., Rehr, J. J., Yabana, K., and Prendergast, David. Wed .
"Velocity-gauge real-time TDDFT within a numerical atomic orbital basis set". United States.
doi:10.1016/j.cpc.2018.01.013.
```

```
@article{osti_1434676,
```

title = {Velocity-gauge real-time TDDFT within a numerical atomic orbital basis set},

author = {Pemmaraju, C. D. and Vila, F. D. and Kas, J. J. and Sato, S. A. and Rehr, J. J. and Yabana, K. and Prendergast, David},

abstractNote = {The interaction of laser fields with solid-state systems can be modeled efficiently within the velocity-gauge formalism of real-time time dependent density functional theory (RT-TDDFT). In this article, we discuss the implementation of the velocity-gauge RT-TDDFT equations for electron dynamics within a linear combination of atomic orbitals (LCAO) basis set framework. Numerical results obtained from our LCAO implementation, for the electronic response of periodic systems to both weak and intense laser fields, are compared to those obtained from established real-space grid and Full-Potential Linearized Augmented Planewave approaches. As a result, potential applications of the LCAO based scheme in the context of extreme ultra-violet and soft X-ray spectroscopies involving core-electronic excitations are discussed.},

doi = {10.1016/j.cpc.2018.01.013},

journal = {Computer Physics Communications},

number = C,

volume = 226,

place = {United States},

year = {Wed Feb 07 00:00:00 EST 2018},

month = {Wed Feb 07 00:00:00 EST 2018}

}