alpha-PbO2-type SiO2
SiO2
Vinet · Original · 2010
V₀
154.8
Bohr³/f.u.
Molar
K₀
329
Isothermal
K′
4.100
dimensionless
Volume (V₀)
| Value | Unit | Basis | Z |
|---|---|---|---|
| 154.8 | Bohr³/f.u. | Molar | — |
| 22.9390 | ų | canonical (converted) | — |
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
- 300 K
- Pref
- —
- Structure
- alpha-PbO2-type (seifertite)
- Method
- first-principles DFT / ab initioQMC (DMC) static energies + DFT(WC) quasiharmonic phonons, fitted with Vinet EOS
- Sample
- QMC computed, Table 1
Source
- Paper
- Quantum Monte Carlo computations of phase stability, equations of state, and el…
- Authors
- K. P. Driver; R. E. Cohen; Zhigang Wu; Burkhard Militzer; Pablo López Ríos; M. D. Towler; R. J. Needs; Jayne Wilkins
- DOI
- 10.1073/pnas.0912130107
- Year
- 2010
- Journal
- Proceedings of the National Academy of Sciences
- Origin
- Original (measured or fitted in the source paper)
Evidence from the paper
TABLE 1. Computed QMC thermal equation of state parameters at ambient conditions (300 K, 0 GPa). alpha-PbO2 QMC: V0 154.8(1), K0 329(4), K0' 4.1(1). 'Analytic equations of state, using the Vinet form, are obtained by fitting isotherms of the Helmholtz free energy.'
Additional notes
F0 Ha per SiO2
-35.7689(2)
alpha x1e-5 K-1
1.2(1)
Cp over R
1.69(1)
gamma
1.27(1)
q
2.05(1)
delta T
6.40(1)
geophysical context
QMC constrains CaCl2-alphaPbO2 transition at the mantle geotherm to 105(8) GPa; transition occurs at 2000-2650 km depth (86-122 GPa), above D'' layer
note
K0 unit not explicitly stated in table; V0 reported per SiO2 formula unit