Wenzhong Wang

Wenzhong Wang
University College London | UCL · Department of Earth Sciences

Doctor of Philosophy

About

43
Publications
11,646
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517
Citations
Additional affiliations
September 2015 - June 2019
University of Science and Technology of China
Position
  • PhD
May 2015 - June 2019
University of Science and Technology of China
Position
  • PhD Student

Publications

Publications (43)
Article
Full-text available
The pyrolite model, which can reproduce the upper-mantle seismic velocity and density profiles, was suggested to have significantly lower velocities and density than seismic models in the lower mantle transition zone (MTZ). This argument has been taken as mineral-physics evidence for a compositionally distinct lower MTZ. However, previous studies o...
Article
Full-text available
To better understand the behaviors of calcium (Ca) isotopes during igneous and metamorphic processes that differentiate the Earth and other rocky planets, we investigated the effects of pressure and Ca/Fe concentration on the average CaO bond length and the reduced partition function ratio of ⁴⁴Ca/⁴⁰Ca (10³ln44/40Caβ) in garnet using first-principl...
Article
Full-text available
How and when Earth’s volatile content was established is controversial with several mechanisms postulated, including planetesimal evaporation, core formation and the late delivery of undifferentiated chondrite-like materials. The isotopes of volatile elements such as sulfur can be fractionated during planetary accretion and differentiation and thus...
Article
Geophysical and geochemical evidence suggests that Earth's core is predominantly made of iron (or iron-nickel alloy) with several percent of light elements. However, Earth's solid inner core transmits shear waves at a much lower velocity than expected from mineralogical models that are consistent with geochemical constraints. Here we investigate th...
Article
The Wu-Wentzcovitch semi-analytical method (SAM) is a concise and predictive formalism to calculate the high-pressure and high-temperature (high-PT) thermoelastic tensor (Cij) of crystalline materials. This method has been successfully applied to materials across different crystal systems in conjunction with ab initio calculations of static elastic...
Article
Full-text available
Diamonds form in a variety of environments between subducted crust, lithospheric and deep mantle. Recently, deep source diamonds with inclusions of the high-pressure H2O-phase ice-VII were discovered. By correlating the pressures of ice-VII inclusions with those of other high-pressure inclusions, we assess quantitatively the pressures and temperatu...
Article
Full-text available
Large Low Shear Velocity Provinces (LLSVPs) in the lowermost mantle are key to understanding the chemical composition and thermal structure of the deep Earth, but their origins have long been debated. Bridgmanite, the most abundant lower-mantle mineral, can incorporate extensive amounts of iron (Fe) with effects on various geophysical properties. H...
Article
Full-text available
Ferromagnesite [(Mg 1−x Fe x)CO 3 ], also referred to as magnesiosiderite at high iron concentration (x > 0.5), is a solid solution of magnesite (MgCO 3) and siderite (FeCO 3). Ferromagnesite is believed to enter the Earth's lower mantle via subduction and is considered a major carbon carrier in the Earth's lower mantle, playing a key role in the E...
Preprint
The Wu-Wenzcovitch semi-analytical method (SAM) to compute the thermoelastic tensor (Cij) (SAM-Cij) is a concise and predictive formalism to calculate the high-pressure and high-temperature (high-PT) Cij of crystalline materials. This method has been successfully applied to materials across different crystal systems in conjunction with ab initio ca...
Article
Full-text available
Earth’s habitability is closely tied to its late-stage accretion, during which impactors delivered the majority of life-essential volatiles. However, the nature of these final building blocks remains poorly constrained. Nickel (Ni) can be a useful tracer in characterizing this accretion as most Ni in the bulk silicate Earth (BSE) comes from the lat...
Article
Barium isotopes could be a novel tracer in low-temperature geochemical processes such as the Ba cycle in rivers and oceans. Equilibrium Ba isotope fractionation between Ba-hosting minerals and aqueous solution is of great importance for the applications of Ba isotopes in geochemistry, but it remains poorly constrained. In this study, we performed f...
Article
The isotopic compositions of iron in major mantle minerals may record chemical exchange between deep-Earth reservoirs as a result of early differentiation and ongoing plate tectonics processes. Bridgmanite (Bdg), the most abundant mineral in the Earth’s lower mantle, can incorporate not only Al but also Fe with different oxidation states and spin s...
Preprint
Full-text available
Ferromagnesite (Mg,Fe)CO3, also referred to as magnesiosiderite at high iron concentration, is a solid solution of magnesite (MgCO3) and siderite (FeCO3). Ferromagnesite is believed to enter the Earth's lower mantle via subduction and is considered as a major carbon carrier in the Earth's lower mantle, playing a key role in the Earth's deep carbon...
Article
The mantle transition zone (MTZ) is potentially a geochemical water reservoir because of the high H2O solubility in its dominant minerals, wadsleyite and ringwoodite. Whether the MTZ is wet or dry fundamentally impacts our understanding of the deep-water distribution, geochemical recycling, and the pattern of mantle convection. However, the water c...
Article
Full-text available
We use density functional theory (DFT) to calculate the equilibrium isotopic fractionation factors of zirconium (Zr) in a variety of minerals including zircon, baddeleyite, Ca-catapleiite, ilmenite, geikielite, magnetite, apatite, K-feldspar, quartz, olivine, clinopyroxene, orthopyroxene, amphibole and garnet. We also report equilibrium fractionati...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Full-text available
Seismic heterogeneities detected in the lower mantle were proposed to be related to subducted oceanic crust. However, the velocity and density of subducted oceanic crust at lower-mantle conditions remain unknown. Here, we report ab initio results for the elastic properties of calcium ferrite‐type phases and determine the velocities and density of o...
Article
The equation of state and elastic properties of akimotoite at simultaneously high pressures and high temperatures are obtained using first-principles calculations based on the density functional theory (DFT). The calculated results agree with the available experimental data. Combining our results with the elastic data of other minerals, we estimate...
Article
Equilibrium Ti isotope fractionation factors among major Ti-bearing minerals are critical for understanding Ti isotope fractionation during magmatic processes. We use the first-principles calculations based on the density functional theory (DFT) to obtain Ti isotope reduced partition function ratios (10³lnβ of ⁴⁹Ti/⁴⁷Ti) in a series of important Ti...
Article
Full-text available
In this study, silicon isotope fractionation factors for metamorphic silicate including muscovite, epidote, and kyanite are calculated using first-principles methods based on density-functional theory. The reduced partition function ratio (103lnβ) of 30Si/28Si decreases in the order of muscovite > epidote ≈ kyanite. Combining with previous calculat...
Article
Velocity and density jumps across the 410-km seismic discontinuity generally indicate olivine contents of ∼30 to 50 vol.% on the basis of the elastic properties of anhydrous olivine and wadsleyite, which is considerably less than the ∼60% olivine in the widely accepted pyrolite model for the upper mantle. A possible explanation for this discrepancy...
Article
Full-text available
Thermodynamic and elastic properties of grossular (Ca3Al2(SiO4)3, the calcium‐aluminium end‐member of garnet) at high pressures and temperatures are obtained using the first‐principles calculations based on the density functional theory. Our calculated results agree well with available experimental data. The elastic moduli and wave velocities of gr...
Article
We report the first measurements of Fe isotope fractionation between coexisting pyrrhotite and chalcopyrite from the Lengshuiqing Ni-Cu magmatic sulfide deposit, Southwest China. The δ⁵⁶Fe values of chalcopyrite (Cp) range from 0.24‰ to 1.25‰, much higher than those in the coexisting pyrrhotite (Po, −1.25‰ to −0.13‰). The δ⁵⁶Fe values of pyroxene s...
Article
Full-text available
Previous theoretical studies have found that the concentration variations within a certain range have a prominent effect on inter-mineral equilibrium isotope fractionation (10³lnα). Based on the density functional theory, we investigated how the average Ca–O bond length and the reduced partition function ratios (10³lnβ) and 10³lnα of ⁴⁴Ca/⁴⁰Ca in f...
Article
Calcium is a major element of the Earth, the Moon, terrestrial planets, and rocky meteorites. Here we present equilibrium Ca isotope fractionation factors of Ca-bearing minerals using the first-principles calculations based on density functional theory (DFT). The sequence of minerals from the isotopically heaviest to the lightest in Ca is forsterit...
Article
Equilibrium Mg isotope fractionation properties between aqueous Mg ²⁺ and minerals are the key for the applications of Mg isotopes in geochemistry. This study conducts first-principles molecular dynamics (FPMD) simulations for aqueous Mg ²⁺ based on the density functional theory (DFT). Thirty-five snapshots are extracted from the FPMD trajectories...
Article
The K concentration effects on K-O bond length and the reduced partition function ratios of 41K/39K in alkali feldspars have been explored using the density function theory (DFT) method. In alkali feldspars, the average K-O bond length increases with increasing K content, measured as K / (K + Na) molar ratio, ranging from 2.724 Å in alkali feldspar...
Article
Full-text available
Here we extend a semianalytical method to compute thermoelastic properties of materials (Wu & Wentzcovitch,) to monoclinic systems and apply it to diopside (MgCaSi2O6), a mineral with monoclinic symmetry and an end-member of clinopyroxene. Using ab initio results for structural and vibrational properties, we obtain the density, the elastic tensor,...
Article
Full-text available
The thermodynamic and elastic properties of corundum at high pressures and temperatures are calculated based on density functional theory within the local density approximation. The calculated results agree well with the available experimental results and provide reliable data up to 80 GPa and 2,500 K. Our results confirm that C14 should be positiv...
Article
Full-text available
Orthopyroxene (opx) is an important mineral in petrologic models for the upper mantle. Its elastic properties are fundamental for understanding the chemical composition and geodynamics of the upper mantle. Here, we calculate the elastic properties of orthoenstatite (MgSiO3), the Mg end-member orthopyroxene under upper-mantle pressure and temperatur...
Article
Full-text available
Ultralow-velocity zones (ULVZs) at Earth's core-mantle boundary region have important implications for the chemical composition and thermal structure of our planet, but their origin has long been debated. Hydrogen-bearing iron peroxide (FeO 2 H x) in the pyrite-type crystal structure was recently found to be stable under the conditions of the lower...
Article
Concentration effect on equilibrium inter-mineral isotope fractionation is ubiquitous in solid solution systems, but it is not clear in which concentration range such effect is prominent. Using first-principles calculations, we examine the effect of Ca and Fe contents in orthopyroxene (opx) on its average Ca–O bond length and the equilibrium Ca iso...
Article
Full-text available
The thermodynamic properties and elasticity of superhydrous phase B (ShyB) at high pressure and temperature are calculated using first principles calculations based on density functional theory. The velocities and densities of ShyB are significantly lower than those of bridgmanite and periclase, the major minerals in the lower mantle. The anisotrop...
Article
Naturally occurring carbonates have a wide variation in Mg and Ca contents. Using the density-functional-theory calculations, this study examines the effect of Mg and Ca concentrations on bond lengths and equilibrium fractionation factors of Mg-Ca isotopes among calcite-type carbonate minerals (MgxCa1-xCO3). Mg content x and Ca content (1-x) of the...
Article
Full-text available
The elasticity of minerals at high temperature and pressure (PT) is critical for constraining the composition and temperature of the Earth’s interior and understand better the deep water cycle and the dynamic Earth. First-principles calculations without introducing any adjustable parameters, whose results can be comparable to experimental data, pla...

Questions

Question (1)
Question
NPT md is so different from NVT md. I set ISIF=3, but the volume and atomic positions of my system did not change during the first 300 steps. I'm total confused. Here are some settings:
MDALGO = 3 LANGEVIN_GAMMA = 10*8 LANGEVIN_GAMMA_L = 1 PMASS = 5.0 TEBEG=650

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Projects (5)
Project
The Innovation is an interdisciplinary journal that aims to promote scientific application by publishing cutting-edge research and high-quality reviews across all scientific disciplines, such as physics, chemistry, materials, nanotechnology, biology, translational medicine, geoscience, and engineering. We strive to adhere to the peer review and publishing standards of Cell Press journals. More information please refer to: https://www.sciencedirect.com/journal/the-innovation http://www.cell.com/the-innovation/home
Project
first principle calculation to understand the characters of minerals and isotopes for exploring the earth interior.