Equation of state data

From here you can download the eos parameters for many phases as '.eos' files. These files can be 'loaded' directly in to the EosFit7 software so that you can do calculations immediately. You can also use EosFit7c to modify the parameters within the files.

Important:
  • Most browsers will download these files. If your browser opens the file, just right-click on the link and select save link as (or save target as in IE).

  • If you use the data in these files, please read the comments and refer to the original literature; you can find the references in the table!




EoS useful for pressure measurement

Quartz The P-V EoS for quartz (SiO2) as determined by Scherdl et al (2016) Journal of Applied Crystallography, 49, 2129-2137. A reprint is available as a pdf file, Copyright International Union of Crystallography.

We use quartz as an internal pressure standard in single-crystal diamond-anvil cell experiments at room temperature. We measure the volume of the quartz by diffraction and use this EoS to convert the measured volume to pressure.

This new EoS extends to 19 GPa. It replaces the previous quartz EoS determined by Angel et al (1997).

Old quartz The P-V EoS for quartz (SiO2) as determined by Angel et al (1997) Journal of Applied Crystallography, 30, 461-466. A reprint is available as a pdf file, Copyright International Union of Crystallography.

You should no longer use this EoS. You should use the new EoS determined by Scherdl et al (2016).
If you want to convert the pressures previously determined by this EoS to the new pressure scale given by Scherdl et al (2016), download both eos files for quartz and use the pshift command in the Edit utility of EosFit7c to convert the pressures in your dataset.


EoS of example datasets distributed with EosFit

These eos files hold the results of fitting the example datasets distributed with EosFit7c. Details of how to fit the data and obtain these results are provided in the 'worked examples' section of the EosFit7 help system.

Quartz The P-V EoS for quartz (SiO2) as determined by Angel et al (1997) Journal of Applied Crystallography, 30, 461-466. A reprint is available as a pdf file, Copyright International Union of Crystallography.

We use quartz as an internal pressure standard in single-crystal diamond-anvil cell experiments. We measure the volume of the quartz by diffraction and use this EoS to convert the measured volume to pressure.

Birch-Murnaghan 3rd order EoS
K0 = 37.12(5) GPa
K' = 5.99(5)
Ferropericlase Equation of state obtained from the pressure-volume-temperature data (up to 2000K and 50GPa) using a BM3 EoS combined with a Berman-type thermal expansion. Beware that data have been only considered up to 50GPa (i.e. well below the spin transition).The original P-V-T data are taken from Mao et al. (2011) GRL 38, L23308
Birch-Murnaghan 3rd order EoS
K0 = 162(14) GPa
K' = 4.1(6)
dK/dT=-0.018(7) GPa/K
alpha0=4.0(6) x 10^-5 /K, alpha1=0.1(6) x 10^-8 K^-2
Kalsilite lowP

Kalsilite highP
Equations of state obtained from the pressure-volume data of kalsilite Gatta et al. (2011) Amer. Mineral. 96, 461. The two eos files are for the low-pressure and high-pressure phases, seperated by a phase transition at ~3.6 GPa. Birch-Murnaghan 3rd order EoS
Low P: K0 = 60 GPa, K' = 3.5
High P: K0 = 44 GPa, K' = 6.5
Lawsonite fit1

Lawsonite fit2
Thermal expansion equations obtained from the V-T data of lawsonite Pawley et al. (1996) Amer. Mineral. 81, 335. Fit1 is a modified Holland-Powell expansion (see EosFit help) and Fit2 has the alpha2 parameter fixed at zero in the Pawley approximation. Modified Holland-Powell expansion
Fit 1: alpha0=1.3(5) x 10^-5 /K, alpha1=-5.5(6) x 10^-4 K^-2
Fit 1: alpha0=5.55(15) x 10^-5 /K, alpha1= 0

EoS useful for host-inclusion calculations

For details about host-inclusion piezobarometry, see:
  • Geobarometry from host-inclusion systems: the role of elastic relaxation. Angel RJ, Mazzucchelli ML, Alvaro M, Nimis P, Nestola F (2014) American Mineralogist, 99, 2146-2149. link

  • How large are departures from lithostatic pressure? Constraints from host-inclusion elasticity. Angel RJ, Nimis P, Mazzucchelli ML, Alvaro M, Nestola F (2015) Journal of Metamorphic Geology, 33, 801-813. link

  • EosFit-Pinc: A simple GUI for host-inclusion elastic thermobarometry. Angel RJ, Mazzucchelli ML, Alvaro M, Nestola F (2017) American Mineralogist, 102, 1957-1960. link

Diamond Our best estimate of the P-V-T EoS for diamond determined from a critical review of the most recent experimental data (elasticity, heat capacity, PV data) and DFT simulations (Angel et al., (2014) Russian Geology & Geophysics, 56,211).



BM3-MGD olivine

BM4-MGD olivine

BM3-Isothermal olivine

BM4-Isothermal olivine
Our best estimate of the P-V-T EoS for mantle composition olivine (Fo90-Fo92) determined from a critical review and a combined fit of elasticity and volume data from single-crystal measurements. Full details in Angel et al., (2018) Physics and Chemistry of Minerals, 45, 95-113.

There are four EoS:
  • BM3-MGD: No elastic softening.
  • BM4-MGD: Includes high-P softening at room temperature.
  • BM3-Isothermal: Includes HT/HP softening, but not the high-P softening at room T.
  • BM4-Isothermal: Includes both HP and HT/HP softening.


Pyrope A P-V-T EoS for pure pyrope garnet derived by Milani et al (2015) Lithos 227, 140-147 from new high-pressure and high-temperature measurements of the volume, combined with low-temperature VT data of Bosenick and Geiger (1997) JGR, Solid Earth 102, 22649.

Almandine A P-V-T EoS for pure pyrope garnet derived by Milani et al (2015) Lithos 227, 140-147 from new high-pressure and high-temperature measurements of the volume, combined with low-temperature VT data.

Grossular A P-V-T EoS for pure grossular garnet determined by Milani et al (2017) American Mineralogist , 102, 851-859 from simultaneous fitting of both volume data and the bulk modulus as determined by Isaak et al (1992) Phys Chem Minerals 19,106-120.

Quartz PVT This is a full P-V-T EoS for quartz, including the elastic softening in both alpha and beta quartz due to the alpha-beta phase transition, and a curved alpha-beta phase boundary to fit all available reversals and constraints. EoS parameters were determined by fitting simultaneously to both elastic moduli and P-T-V data. For details about this and the next two EoS for quartz see Angel et al (2017) Contribs. Min. Pet., 172:29 or contact us.

Quartz V and a This file contains the full P-V-T EoS of quartz and the EoS for the a-cell parameter, both in Angstroms. They can be used together to determine how the a,b,c and V of quartz change with P and T, in a self-consistent way in the CELL utility of EosFit7c. See Alvaro et al (2020) Geology, 48:24 and Angel RJ, Mazzucchelli ML, Gonzalez-Platas J, Alvaro M, F (2022) A self-consistent approach to determine unit-cell parameter variations with pressure and temperature. In preparation.

The PVT EoS is the same as the previous one, but with volumes in A3/cell. The EoS for the a-cell parameter was determined with the same transition model by fitting the same sources of data. Please reference Alvaro et al (2020) Geology, 48:24 as the source.

Quartz PVT This is a full P-V-T EoS for quartz, including the elastic softening in both alpha and beta quartz due to the alpha-beta phase transition, but with a linear alpha-beta phase boundary with slope of 240GPa/K, from Thermocalc. EoS parameters were determined by fitting simultaneously to both elastic moduli and P-T-V data. From Angel et al (2017) Contribs. Min. Pet., 172:29.

Quartz PVT This is a P-V-T EoS for quartz using a model similar to that in Thermocalc, with elastic softening only in alpha quartz. Linear alpha-beta phase boundary with slope of 240GPa/K, from Thermocalc. These EoS parameters were determined by fitting simultaneously to both elastic moduli and P-T-V data and can be used with Thermocalc. From Angel et al (2017) Contribs. Min. Pet., 172:29.

Rutile a-axis

Rutile c-axis

Rutile V
These are EoS for the cell parameters and the volume of rutile determined by fitting simultaneously to both elastic moduli and diffraction data in the literature. Full details in a manuscript by Zaffiro et al. (2019), Mineralogical Magazine, 83:339.

You can try fitting the data yourself with the three dataset files for rutile formatted for EosFit:
cell parameters and volume dataset
adiabatic linear and bulk moduli at high T
adiabatic bulk moduli at high P

To use these files, remove the '.txt' extension from the file name.

Rutile MGD

Rutile qcompMGD
These are two versions of the MGD EoS fitted to the same data for rutile. One is the general form of the MGD with a refined value of the q-parameter, and the other is the q-compromise version. Both provide a very similar PVT relationship as the 'isothormal' PVT EoS given above, but may be more reliable at more extreme P and T.

For a discussion of the role of the q-parameter in MGD EoS, the concept of q-compromise EoS, and a comparison of different EoS of rutile see Angel et al. (2020), Mineralogical Magazine, 84:355-357.

Zircon MGD This is an MGD EoS fitted to new PV and elasticity data for zircon, together with literature TV data. This EoS has been developed by Alix Ehlers of Virginia Tech. Full details of the data and fitting are in Ehlers et al (2021) American Mineralogist, 106, in press which is currently availabe as a preprint.

If you use this EoS, please reference it for now as Ehlers et al (2021) in press, and check with us or the American Mineraogist website for an updated reference prior to your final publication.

Zircon a,c,V EoS
These are isothermal-type EoS for the zircon volume and unit-cell parameters fitted to the same datasets as described for the MGD EoS for zircon.

All three eoS are loaded in one eos file. You can chose the individual eos (a, c, or V) out of the file with the load command of EosFit7c, or you can load them all simultaneously from this file into the CELL utility of EosFit7c. The EosFit-GUI and calculator will automatically read the first EoS in the file, which is for the volume.

If you use these EoS, please reference them for now as Ehlers et al (2021) American Mineralogist, 106, in press, and check with us or the American Mineraogist website for an updated reference prior to your final publication.