SiO2 modified-fluorite
SiO2
third-order Birch-Murnaghan · Original · 1993
V₀
42.9
ų
Unit cell
K₀
387
GPa
Isothermal
K′
4.400
dimensionless
Volume (V₀)
| Value | Unit | Basis | Z |
|---|---|---|---|
| 42.9 | ų | Unit cell | — |
Reported value and unit are preserved as extracted. Z (formula units per cell) is not stored yet, so molar ↔ ų/f.u. conversion is not applied automatically.
Composition
| Oxide | Molar |
|---|---|
| SiO2 | 1 |
Formula: SiO2
Conditions & method
- Tref
- —
- Pref
- —
- Structure
- other / unspecified
- Method
- first-principles DFT / ab initioab initio periodic Hartree-Fock (CRYSTAL88), static 0 K energy-volume fit with oxygen positional parameter u optimized at each volume
- Sample
- ab initio periodic Hartree-Fock total energies, this work
Source
- Paper
- Equation of state and high‐pressure phase transitions of stishovite (SiO2): Ab …
- Authors
- David Μ. Sherman
- DOI
- 10.1029/93jb00783
- Year
- 1993
- Journal
- Journal of Geophysical Research Atmospheres
- Origin
- Original (measured or fitted in the source paper)
Evidence from the paper
The energy curve was fit to a third-order Birch-Murnaghan equation to give K0 = 387 GPa, K' = 4.4, and V0 = 42.9 A^3 (for a unit cell with 2 SiO2).
Additional notes
note
Unit cell contains 2 SiO2 formula units. Zero-pressure density ~7.5% greater than stishovite, but internal energy too high (131 kJ/mol above stishovite at zero pressure) to stabilize the phase.
context
Candidate post-stishovite phase evaluated for lower-mantle/D'' relevance.