3rd BM EOS - Katsura's High-Pressure Earth
The concept of the 3 rd-order Birch-Murnaghan equation of state (BM3-EOS) is almost the same as that of the 2 nd-order Birch-Murnaghan equation of state (BM2-EOS). Difference is that change in Helmholtz free energy, F , is expanded not to the 2 nd -order ( BM2 Eq. 3 ) but to the 3 rd -order the finite strain f ( BM2 Eq. 2 ):
黑柱石的高压相变及其压缩性研究 - pku.edu.cn
从 α 相和 β 相黑柱石的bm3-eos 曲线(图 3)可以看出, 当黑柱石从 α 相转变为 β 相时, 状态方程曲线的斜率变小, 表明高压 β相黑柱石的体积模量 k 0 较大, 更难压缩。但是, 在相变过程中, 黑柱石的体积并没有发生明显的不连续变化。
The thermal equation of state of the magma Ocean
2024年7月1日 · The parameters of the athermal 3rd (BM3) and 4th (BM4) order Birch-Murnaghan equations of state (EOS) were obtained by fitting the pressure–density points along isotherms in the 2000 – 5500 K below 180 GPa. Due to the vicinity of the critical temperature, the fits to the 6000 K isotherm data fail.
Phase Transition of Enstatite‐Ferrosilite Solid Solutions at High ...
2020年5月12日 · The P-V data of the four orthopyroxenes within the α-opx phase region were fitted to the third-order Birch-Murnaghan-EoS (BM3-EoS; Birch, 1947) to obtain the EoS parameters including the zero-pressure volume (V T0), isothermal bulk modulus (K T0), and its pressure derivative (K′ T0).
Equations of State - Alberto's repos
2025年3月30日 · In order to calculate the volume derivatives of the energy, an analytical expression needs to be fitted to the input data. This mathematical expression, commonly known as the equation of state (EOS), can take many forms. Which equation of state is used for a particular phase is determined by the FIT option to PHASE: PHASE ...
Thermoelastic Properties of Eclogitic Garnets and Omphacites ...
2019年1月2日 · During the calculation, we used the HT-BM3-EoS and the obtained thermoelastic parameters of eclogitic garnets and omphacites. In this model, the eclogite consists of 20 vol% garnet, 75 vol% omphacite, and 5 vol% coesite (Nishi et al., 2009), and the densities of eclogite assemblages are estimated by using a Voigt-Reuss-Hill average (Hill, 1952).
High pressure structure studies of three SrGeO3 polymorphs ...
2021年2月25日 · We found that the obtained amorphous polymorph was stable at ambient pressure. The third-order Birch-Murnaghan (BM3) EoS model was fitted to the volume data obtained in the pressure range from 0 to 10 GPa for both the PXRD and the single-crystal study and a plot of the volume vs. pressure together with the resulting EoS fits are shown in Fig. 4 ...
The Birch-Murnaghan equation of state parameters of third order (EoS …
The Birch-Murnaghan equation of state parameters of third order (EoS BM3): V 0 , B 0 , B 1 and second order (EoS BM2): V 0 , B 0 , (B 1 = 4.0), calculated using functional B3LYP and from...
Elasticity and lattice dynamics of enstatite at high pressure
2013年7月25日 · We combine density functional theory with Mössbauer spectroscopy and NRIXS to understand the local site symmetry of the Fe atoms in our sample. A third-order Birch-Murnaghan (BM3) equation of state fitting gives KT0 =103±5 GPa and KT 0′=13±2 for the Pbca phase. At 12 GPa, a BM3 fitting gives KT12 =220±10 GPa with KT 12′=8±4 for the P21/c phase.
Thermal equations of state of B2-structured rubidium halides …
2025年3月17日 · In this study, we determined the thermal equations of state (EoS) for rubidium chloride (RbCl), rubidium bromide (RbBr), and rubidium iodide (RbI) in the B2 (CsCl-type) structure. We conducted in situ energy-dispersive x-ray diffraction measurements at high pressures (up to 26 GPa) and temperatures (up to 1800 K) using a large volume press.