# Electronic structure and metallization of cubic GdH{sub 3} under pressure: Ab initio many-body GW calculations

## Abstract

The electronic structures of the cubic GdH{sub 3} are extensively investigated using the ab initio many-body GW calculations treating the Gd 4f electrons either in the core (4f-core) or in the valence states (4f-val). Different degrees of quasiparticle (QP) self-consistent calculations with the different starting points are used to correct the failures of the GGA/GGA + U/HSE03 calculations. In the 4f-core case, GGA + G{sub 0}W{sub 0} calculations give a fundamental band gap of 1.72 eV, while GGA+ GW{sub 0} or GGA + GW calculations present a larger band gap. In the 4f-val case, the nonlocal exchange-correlation (xc) functional HSE03 can account much better for the strong localization of the 4f states than the semilocal or Hubbard U corrected xc functional in the Kohn–Sham equation. We show that the fundamental gap of the antiferromagnetic (AFM) or ferromagnetic (FM) GdH{sub 3} can be opened up by solving the QP equation with improved starting point of eigenvalues and wave functions given by HSE03. The HSE03 + G{sub 0}W{sub 0} calculations present a fundamental band gap of 2.73 eV in the AFM configuration, and the results of the corresponding GW{sub 0} and GW calculations are 2.89 and 3.03 eV, respectively. In general, for the cubic structure, the fundamental gap from G{sub 0}W{sub 0} calculations inmore »

- Authors:

- School of Physics and Electronic Sciences, Guizhou Education University, Guiyang 550018 (China)
- (China)
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018 (China)

- Publication Date:

- OSTI Identifier:
- 22597890

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Applied Physics; Journal Volume: 120; Journal Issue: 1; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANTIFERROMAGNETISM; COMPRESSION; CONFIGURATION; DEFECTS; EIGENVALUES; ELECTRON CORRELATION; ELECTRONIC STRUCTURE; ELECTRONS; EQUATIONS; FAILURES; FORECASTING; GADOLINIUM HYDRIDES; HYDROGEN; MANY-BODY PROBLEM; METALS; PRESSURE RANGE GIGA PA; VALENCE; WAVE FUNCTIONS

### Citation Formats

```
Kong, Bo, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn, Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, and Zhang, Yachao, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn.
```*Electronic structure and metallization of cubic GdH{sub 3} under pressure: Ab initio many-body GW calculations*. United States: N. p., 2016.
Web. doi:10.1063/1.4955050.

```
Kong, Bo, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn, Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, & Zhang, Yachao, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn.
```*Electronic structure and metallization of cubic GdH{sub 3} under pressure: Ab initio many-body GW calculations*. United States. doi:10.1063/1.4955050.

```
Kong, Bo, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn, Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, and Zhang, Yachao, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn. Thu .
"Electronic structure and metallization of cubic GdH{sub 3} under pressure: Ab initio many-body GW calculations". United States. doi:10.1063/1.4955050.
```

```
@article{osti_22597890,
```

title = {Electronic structure and metallization of cubic GdH{sub 3} under pressure: Ab initio many-body GW calculations},

author = {Kong, Bo, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn and Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018 and Zhang, Yachao, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn},

abstractNote = {The electronic structures of the cubic GdH{sub 3} are extensively investigated using the ab initio many-body GW calculations treating the Gd 4f electrons either in the core (4f-core) or in the valence states (4f-val). Different degrees of quasiparticle (QP) self-consistent calculations with the different starting points are used to correct the failures of the GGA/GGA + U/HSE03 calculations. In the 4f-core case, GGA + G{sub 0}W{sub 0} calculations give a fundamental band gap of 1.72 eV, while GGA+ GW{sub 0} or GGA + GW calculations present a larger band gap. In the 4f-val case, the nonlocal exchange-correlation (xc) functional HSE03 can account much better for the strong localization of the 4f states than the semilocal or Hubbard U corrected xc functional in the Kohn–Sham equation. We show that the fundamental gap of the antiferromagnetic (AFM) or ferromagnetic (FM) GdH{sub 3} can be opened up by solving the QP equation with improved starting point of eigenvalues and wave functions given by HSE03. The HSE03 + G{sub 0}W{sub 0} calculations present a fundamental band gap of 2.73 eV in the AFM configuration, and the results of the corresponding GW{sub 0} and GW calculations are 2.89 and 3.03 eV, respectively. In general, for the cubic structure, the fundamental gap from G{sub 0}W{sub 0} calculations in the 4f-core case is the closest to the real result. By G{sub 0}W{sub 0} calculations in the 4f-core case, we find that H or Gd defects can strongly affect the band structure, especially the H defects. We explain the mechanism in terms of the possible electron correlation on the hydrogen site. Under compression, the insulator-to-metal transition in the cubic GdH{sub 3} occurs around 40 GPa, which might be a satisfied prediction.},

doi = {10.1063/1.4955050},

journal = {Journal of Applied Physics},

number = 1,

volume = 120,

place = {United States},

year = {Thu Jul 07 00:00:00 EDT 2016},

month = {Thu Jul 07 00:00:00 EDT 2016}

}