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Post-stishovite (CaCl₂-type)

SiO2

third-order Birch-Murnaghan · Original · 2019

Why this differs from similar rows?

Table 1 'This study' model with q fixed to 1 (same as Table 2 Model 2); sibling rows in Table 2 use different fixed q values (0.8, 1.2), which change the fitted K_T0.

V₀
48.1
ų
Unit cell
K₀
245
GPa
Isothermal
K′
4
dimensionless

Volume (V₀)

Value Unit Basis Z
48.1 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

OxideMolar
SiO21

Formula: SiO2

Conditions & method

Tref
300 K
Pref
Structure
CaCl2-type SiO2
Method
experiment (XRD / DAC / multianvil compression)
synchrotron XRD in laser-heated diamond anvil cell
Sample
This study, Table 1 (q = 1 fixed, Model 2)

Source

Paper
High Pressure‐Temperature Study on the Thermal Equations of State of Seifertite…
Authors
Ningyu Sun; Weigang Shi; Zhu Mao; Cijin Zhou; Vitali B. Prakapenka
DOI
10.1029/2019jb017853
Year
2019
Journal
Journal of Geophysical Research Solid Earth
Origin
Original (measured or fitted in the source paper)

Evidence from the paper

For CaCl2-type SiO2, we obtained a bulk modulus, K_T0 = 245(7) GPa with a fixed K_T' = 4, V0 = 48.1(2) Å3, γ0 = 1.3(3), q = 1 (fixed), and θ_D0 = 1100 (400) K. (Table 1: This study 245 (7), 4 (fixed), 48.1 (2), 1100 (400), 1.3 (3), 1 (fixed))

Additional notes

theta D0 K
1100 (400)
gamma 0
1.3 (3)
q
1 (fixed)
pressure scale
NaCl thermal EoS (Fei et al., 2007)
P T range
55–147 GPa, up to 3500 K