Abstract
Based on density-functional total-energy pseudopotential calculations, we find that diamond structure carbon becomes energetically unstable relative to a highly distorted tetrahedrally coordinated structure at pressures above 5.0 Mbar. This distorted phase has a rhombohedral crystal structure containing eight atoms (denoted as the R8 structure) and has recently been identified experimentally as a pressure-induced metastable phase of silicon. This result has profound implications for ultrahigh pressure experimentation as it places a substantially lower limit on the maximum pressures attainable with diamond-anvil cell technology than was believed to exist previously. © 1995 The American Physical Society.
Original language | English |
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Pages (from-to) | 15035-15038 |
Number of pages | 4 |
Journal | Physical review B |
Volume | 52 |
Issue number | 21 |
Publication status | Published - 1 Dec 1995 |
Keywords / Materials (for Non-textual outputs)
- ANVIL CELL
- PSEUDOPOTENTIALS
- CARBON