Phase H
MgSiO4H2
Birch-Murnaghan (order unspecified) · Original · 2015
V₀
58.9
ų
Unit cell
K₀
147.500
GPa
Unknown
K′
4.900
dimensionless
Volume (V₀)
| Value | Unit | Basis | Z |
|---|---|---|---|
| 58.9 | 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 |
|---|---|
| MgO | 1 |
| SiO2 | 1 |
| H2O | 1 |
Formula: MgSiO4H2
Conditions & method
- Tref
- —
- Pref
- —
- Structure
- other / unspecified
- Method
- first-principles DFT / ab initiofirst principles DFT (GGA, plane-wave pseudopotential, Quantum-Espresso), static 0 K structural relaxations 0-100 GPa
- Sample
- first-principles simulation (static, model-1)
Source
- Paper
- Crystal structure, equation of state and elasticity of phase H (MgSiO4H2) at Ea…
- Authors
- Jun Tsuchiya; Mainak Mookherjee
- DOI
- 10.1038/srep15534
- Year
- 2015
- Journal
- Scientific Reports
- Origin
- Original (measured or fitted in the source paper)
Evidence from the paper
The pressure-volume results for phase H are well described by the finite strain formulation of Birch-Murnaghan (Fig. 2) with a zero pressure bulk modulus K_O of 147.5 (±6.8) GPa, the pressure derivative of the zero pressure bulk modulus K_O' of 4.9 (±0.2), and a zero pressure unit-cell volume V_O of 58.9 (±0.2) ų. ... All structural parameters are fully relaxed at a static 0 K and 0–100 GPa.
Additional notes
context
Phase H is a dense hydrous magnesium silicate (DHMS) stable at Earth's lower mantle pressures (>30 GPa); isostructural with δ-AlOOH
K Hill at 0GPa
148.7 GPa (Table 2, Voigt-Reuss-Hill from elastic constants)
G Hill at 0GPa
112.7 GPa (Table 2)
density at 0GPa
3.338 g/cm3 (Table 1)
hydrogen bond symmetrization
~30 GPa; anomalous elastic behavior of C11, C22, C23, C16, C26, C66 and K near 20–30 GPa
computational details
GGA exchange-correlation, norm-conserving pseudopotentials, 80 Ry cutoff, 4×4×6 Monkhorst-Pack mesh