## Time-dependent density functional theory with twist-averaged boundary conditions

## Abstract

Time-dependent density functional theory is widely used to describe excitations of many-fermion systems. In its many applications, three-dimensional (3D) coordinate-space representation is used, and infinitedomain calculations are limited to a finite volume represented by a spatial box. For finite quantum systems (atoms, molecules, nuclei, hadrons), the commonly used periodic or reflecting boundary conditions introduce spurious quantization of the continuum states and artificial reflections from boundary; hence, an incorrect treatment of evaporated particles. The finite-volume artifacts for finite systems can be practically cured by invoking an absorbing potential in a certain boundary region sufficiently far from the described system. However, such absorption cannot be applied in the calculations of infinite matter (crystal electrons, quantum fluids, neutron star crust), which suffer from unphysical effects stemming from a finite computational box used. Here, twist-averaged boundary conditions (TABC) have been used successfully to diminish the finite-volume effects. In this work, we extend TABC to time-dependent modes. We demonstrate that by using TABC, one can reduce finite-volume effects drastically without adding any additional parameters associated with absorption at large distances. Moreover, TABC are an obvious choice for time-dependent calculations for infinite systems. Furthermore, since TABC calculations for different twists can be performed independently, the methodmore »

- Authors:

- Michigan State Univ., East Lansing, MI (United States)
- Michigan State Univ., East Lansing, MI (United States); Univ. of Warsaw, Warsaw (Poland)
- Univ. Erlangen, Erlangen (Germany)

- Publication Date:

- Research Org.:
- Michigan State Univ., East Lansing, MI (United States)

- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA)

- OSTI Identifier:
- 1332818

- Alternate Identifier(s):
- OSTI ID: 1250550

- Grant/Contract Number:
- NA0002847; DOE-DE-NA0002847; SC0008511

- Resource Type:
- Accepted Manuscript

- Journal Name:
- Physical Review C

- Additional Journal Information:
- Journal Volume: 93; Journal Issue: 5; Journal ID: ISSN 2469-9985

- Publisher:
- American Physical Society (APS)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS

### Citation Formats

```
Schuetrumpf, B., Nazarewicz, Witold, and Reinhard, P. -G. Time-dependent density functional theory with twist-averaged boundary conditions. United States: N. p., 2016.
Web. doi:10.1103/PhysRevC.93.054304.
```

```
Schuetrumpf, B., Nazarewicz, Witold, & Reinhard, P. -G. Time-dependent density functional theory with twist-averaged boundary conditions. United States. doi:10.1103/PhysRevC.93.054304.
```

```
Schuetrumpf, B., Nazarewicz, Witold, and Reinhard, P. -G. Mon .
"Time-dependent density functional theory with twist-averaged boundary conditions". United States. doi:10.1103/PhysRevC.93.054304. https://www.osti.gov/servlets/purl/1332818.
```

```
@article{osti_1332818,
```

title = {Time-dependent density functional theory with twist-averaged boundary conditions},

author = {Schuetrumpf, B. and Nazarewicz, Witold and Reinhard, P. -G.},

abstractNote = {Time-dependent density functional theory is widely used to describe excitations of many-fermion systems. In its many applications, three-dimensional (3D) coordinate-space representation is used, and infinitedomain calculations are limited to a finite volume represented by a spatial box. For finite quantum systems (atoms, molecules, nuclei, hadrons), the commonly used periodic or reflecting boundary conditions introduce spurious quantization of the continuum states and artificial reflections from boundary; hence, an incorrect treatment of evaporated particles. The finite-volume artifacts for finite systems can be practically cured by invoking an absorbing potential in a certain boundary region sufficiently far from the described system. However, such absorption cannot be applied in the calculations of infinite matter (crystal electrons, quantum fluids, neutron star crust), which suffer from unphysical effects stemming from a finite computational box used. Here, twist-averaged boundary conditions (TABC) have been used successfully to diminish the finite-volume effects. In this work, we extend TABC to time-dependent modes. We demonstrate that by using TABC, one can reduce finite-volume effects drastically without adding any additional parameters associated with absorption at large distances. Moreover, TABC are an obvious choice for time-dependent calculations for infinite systems. Furthermore, since TABC calculations for different twists can be performed independently, the method is trivially adapted to parallel computing.},

doi = {10.1103/PhysRevC.93.054304},

journal = {Physical Review C},

number = 5,

volume = 93,

place = {United States},

year = {2016},

month = {5}

}

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Web of Science

Works referenced in this record:

##
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- Giannozzi, Paolo; Baroni, Stefano; Bonini, Nicola
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