# Equation of state of dense plasmas by ab initio simulations: Bridging the gap between quantum molecular dynamics and orbital-free molecular dynamics at high temperature

## Abstract

The applicability of quantum molecular dynamics to the calculation of the equation of state of a dense plasma is limited at high temperature by computational cost. Orbital-free molecular dynamics, based on the Thomas-Fermi semiclassical approximation and possibly on a gradient correction, is the only simulation method currently available at high temperature. We show in the case of a dense boron plasma that the two approaches give pressures differing by a few percent even at temperatures as high as a few tens of electron-volts. We indicate how the pressures obtained by orbital-free molecular dynamics can be corrected in order to appear as a limit of the quantum molecular dynamics results as temperature increases. We thus obtain a method to calculate the equation of state of a dense plasma up to high temperatures where quantum molecular dynamics cannot be directly implemented.

- Authors:

- CEA, DAM, DIF, F-91297 Arpajon (France)

- Publication Date:

- OSTI Identifier:
- 22072650

- Resource Type:
- Journal Article

- Journal Name:
- Physics of Plasmas

- Additional Journal Information:
- Journal Volume: 19; Journal Issue: 12; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 74 ATOMIC AND MOLECULAR PHYSICS; BORON; EQUATIONS OF STATE; MOLECULAR DYNAMICS METHOD; PLASMA; PLASMA DENSITY; PLASMA SIMULATION; SEMICLASSICAL APPROXIMATION; TEMPERATURE RANGE 0400-1000 K; THOMAS-FERMI MODEL

### Citation Formats

```
Danel, J.-F., Kazandjian, L., and Zerah, G.
```*Equation of state of dense plasmas by ab initio simulations: Bridging the gap between quantum molecular dynamics and orbital-free molecular dynamics at high temperature*. United States: N. p., 2012.
Web. doi:10.1063/1.4773191.

```
Danel, J.-F., Kazandjian, L., & Zerah, G.
```*Equation of state of dense plasmas by ab initio simulations: Bridging the gap between quantum molecular dynamics and orbital-free molecular dynamics at high temperature*. United States. doi:10.1063/1.4773191.

```
Danel, J.-F., Kazandjian, L., and Zerah, G. Sat .
"Equation of state of dense plasmas by ab initio simulations: Bridging the gap between quantum molecular dynamics and orbital-free molecular dynamics at high temperature". United States. doi:10.1063/1.4773191.
```

```
@article{osti_22072650,
```

title = {Equation of state of dense plasmas by ab initio simulations: Bridging the gap between quantum molecular dynamics and orbital-free molecular dynamics at high temperature},

author = {Danel, J.-F. and Kazandjian, L. and Zerah, G.},

abstractNote = {The applicability of quantum molecular dynamics to the calculation of the equation of state of a dense plasma is limited at high temperature by computational cost. Orbital-free molecular dynamics, based on the Thomas-Fermi semiclassical approximation and possibly on a gradient correction, is the only simulation method currently available at high temperature. We show in the case of a dense boron plasma that the two approaches give pressures differing by a few percent even at temperatures as high as a few tens of electron-volts. We indicate how the pressures obtained by orbital-free molecular dynamics can be corrected in order to appear as a limit of the quantum molecular dynamics results as temperature increases. We thus obtain a method to calculate the equation of state of a dense plasma up to high temperatures where quantum molecular dynamics cannot be directly implemented.},

doi = {10.1063/1.4773191},

journal = {Physics of Plasmas},

issn = {1070-664X},

number = 12,

volume = 19,

place = {United States},

year = {2012},

month = {12}

}