The Pseudopotential Approach within Density-Functional Theory: The Case of Atomic Metallic Hydrogen
Internal energies, enthalpies, phonon dispersion curves, and superconductivity of atomic metallic hydrogen are calculated. The standard use of pseudopotentials in density-functional theory are compared with full Coulomb-potential, all-electron linear muffin-tin orbital calculations. Quantitatively s...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-11-01
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| Series: | Condensed Matter |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2410-3896/5/4/74 |
| Summary: | Internal energies, enthalpies, phonon dispersion curves, and superconductivity of atomic metallic hydrogen are calculated. The standard use of pseudopotentials in density-functional theory are compared with full Coulomb-potential, all-electron linear muffin-tin orbital calculations. Quantitatively similar results are found as far as internal energies are concerned. Larger differences are found for phase-transition pressures; significant enough to affect the phase diagram. Electron–phonon spectral functions <inline-formula><math display="inline"><semantics><mrow><msup><mi>α</mi><mn>2</mn></msup><mi>F</mi><mrow><mo>(</mo><mi>ω</mi><mo>)</mo></mrow></mrow></semantics></math></inline-formula> also show significant differences. Against expectation, the estimated superconducting critical-temperature <i>T</i><inline-formula><math display="inline"><semantics><msub><mrow></mrow><mi>c</mi></msub></semantics></math></inline-formula> of the first atomic metallic phase I4<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>1</mn></msub></semantics></math></inline-formula>/amd (Cs-IV) at 500 GPa is actually higher. |
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| ISSN: | 2410-3896 |