Diopside-hedenbergite solid solution is the most common clinopyroxene end-member combination in mafic and ultramafic igneous rocks. The crystal structure variety caused by Mg-Fe isomorphous substitution can indicate geological processes such as Mg-Fe isotope fractionation. To explore the effect of Hubbard U correction and Fe content on iron-bearing clinopyroxene structures, we employed GGA and GGA + U to study the lattice constants, unit-cell volume, and average Fe-O bond length of the diopside-hedenbergite solid solution series. On the whole, the results by GGA + U are the increase in lattice constant a (from 9.910 & Aring; to 10.030 & Aring;) and volume (from 456.656 & Aring;(3) to 464.640 & Aring;(3)), the decrease in beta angle (from 106.121 degrees to 105.320 degrees), and a slight variation in the lattice constant b (from 9.007 & Aring; to 9.010 & Aring;) with increasing Fe content, which is a better match with the experiment than those by GGA. The average Fe-O bond lengths and polyhedral volumes calculated by GGA and GGA + U both increase with increasing Fe content. The Hubbard U correction significantly affects the lattice constants and unite-cell volume at medium-high Fe content (Fe/(Ca+ Mg + Fe) > 2/8), the Fe-O bond at low Fe content (Fe/(Ca+ Mg + Fe) < 1/8), the bond angle variance, distortion index and quadratic elongation at relatively medium Fe content (1/8 <= Fe/(Ca+ Mg + Fe) <= 5/16). This study verifies the effectiveness of U-value correction on iron-bearing clinopyroxene and provides a theoretical basis for understanding its structural evolution.

Chlorine (Cl) and sulfur (S) are two crucial mineralizing agents in silicate melts, and are closely related to the genesis of metallic mineral deposits. Magmatic ore deposits usually form in mafic-ultramafic silicate melts by the separation (liquation) of a cooling, sulfur-rich magma into two immiscible liquids. It is not easy to identify the complexation between gold (Au), cooper (Cu) and Cl, S using the current experiment methods, and the coordination of Au and Cu with Cl and S is still unclear in mafic-ultramafic silicate melts. In this study, by using first-principles molecular dynamics technique, we investigated the structure of Au, Cu, Cl and S in the (a) anhydrous and (b) hydrous peridotite melt to reveal their coordination geochemistry. Our results show that Si4+-Cl-, Cu+-O2-, Au+-O2-, Cu+-Cl-, Au+-Cl-, Au+-S2-, and Cu+-S2- cannot form stable ion pairs in silicate melts; therefore, Au+ and Cu+ cannot form stable complexes with S2-, O2- or Cl- in the melts. But the diffusion coefficients of Au+, Cu+, S2- and Cl-, their RDF values and the bonding time ratio of the silicate melt systems show that, although they cannot form stable complexes, within the range of effective chemical bond lengths, they have a high probability of approaching and interacting with each other, which enables them to form crystal embryos or liquid-phase molecules during magma evolution.

Tellurium is a critical metal that is highly concentrated in tellurides, which also serve as important hosts of gold, silver, and platinum-group elements. Understanding the stable isotopic behavior of Te in tellurides is crucial not only for elucidating the formation and evolution of Te-bearing hydrothermal ore systems but also for constraining the genetic mechanisms of gold deposits. However, Te isotope fractionation in tellurides remains poorly characterized and inadequately understood. In this study, first-principles calculations were used to determine Te isotope fractionation between tellurides and native tellurium. The reduced partition function ratios of Te-130/Te-125 are found to decrease in the following order: frohbergite (FeTe2) > mattagamite (CoTe2) > vulcanite (CuTe) > pampaloite (AuSbTe) > petzite (Ag3AuTe2) > melonite (NiTe2) > sylvanite (AuAgTe4) >= coloradoite (HgTe) >= st & uuml;tzite (Ag5Te3) > krennerite (Au3AgTe8) > hessite (Ag2Te) > calaverite (AuTe2) >= montbrayite (Au2Te3) > tellurantimony (Sb2Te3) >= skippenite (Bi2Se2Te) >= Jos & eacute;ite-A (Bi4TeS2) > tellurobismuthite (Bi2Te3) > native tellurium >= tsumoite (BiTe) > altaite (PbTe). The beta(130)(-)(125) factors of tellurides show a weak correlation with Te coordination number, but they exhibit a negative correlation with the average length of chemical bonds formed by Te when minerals are grouped by Te coordination number and oxidation state. Our results provide a theoretical basis for determining whether isotopic equilibrium has been achieved in natural samples and enable more accurate interpretations of variations in Te isotopic compositions. This, in turn, advances our understanding of the formation and evolution of gold-telluride deposits.

Organic ligands have been suggested to play a key role in controlling root-to-shoot transport and isotope fractionation of cadmium (Cd) in crops. In this work, we used the Donnan membrane technique to determine the Cd equilibrium isotope fractionation that is induced by the chelation of Cd with low-molecular weight organic ligands. While a model ligand with oxygen and nitrogen functional groups (EDTA, R-OH, R-NH) induced no significant isotope fractionation between complexed and free Cd2+ (Delta 114/110CdCdEDTA - freeCd = -0.08 +/- 0.12 parts per thousand; n = 4), the model ligand with sulfur donor groups (DMPS, R-SH) induced a strong isotope fractionation (Delta 114/110CdCdDMPS - freeCd = -0.66 +/- 0.20 parts per thousand; n = 4). These experimental results indicate that binding of Cd to thiols plays a major role in retaining light Cd isotopes in roots and shoots, thereby minimizing transfer to cereal grains.

The water migration in subduction zones, primarily driven by the phase transition in hydrous minerals, can give rise to hydrated regions with reduced velocity. A fundamental element in comprehending and deciphering these low-velocity zones revolves around acquiring insights into the stability and elasticity of relevant hydrous minerals. As one of the main water carriers in shallow areas, antigorite can dehydrate to form talc, forsterite, and fluid (talc-bearing peridotites) in deep areas of subduction zones, and then the talc thus serves as one of the minerals that can bring water to the deep Earth. Here, the elasticity of talc up to 24 GPa and forsterite up to 12 GPa are calculated by using the first principles method. The result supposes that the talc structure transforming from talc I to talc II is at a pressure between 6 GPa and 8 GPa, impacting the trend of elastic wave velocity in response to pressure. Furthermore, the elastic wave velocity of forsterite can be significantly affected by iron concentration. Meanwhile, a variation velocity model with antigorite consumption and talc content is set up for talc-bearing serpentinized peridotite based on the elastic properties of talc and forsterite in this study, and antigorite in Wang et al. (2022). The results of our model demonstrate a decrease in the low-velocity anomaly in subduction zones, particularly in deep regions or areas with higher initial serpentinization degrees. The results also suggest that the mode of antigorite dehydration can diminish the estimation of water content transported to depths of subduction zones, such as the Mariana Trench and Northern Japan subduction zones. The mode of antigorite dehydration thus provides a useful tool for constraining the composition, seismic velocity structure, and water migration in subduction zones. (c) 2024 China University of Geosciences (Beijing) and Peking University. Published by Elsevier B.V. on behalf of China University of Geosciences (Beijing). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

This evolution may comprise stages, such as arise, generate, develop, increase, and trigger, from initial linear to complex nonlinear chaos/turbulence. Based on the improved relativistic hybrid particle-in-cell and lattice Boltzmann method development in Paper I of this series of studies [Zhu et al., "Relativistic HPIC-LBM and its application in large temporal-spatial turbulent magnetic reconnection. Part I. Model development and validation," Appl. Math. Modell. 78, 932-967 (2020); Zhu et al., "Electron acceleration in interaction of magnetic islands in large temporal-spatial turbulent magnetic reconnection," Earth Planet. Phys. 3, 17-25 (2019); Zhu et al., "Relativistic HPIC-LBM and its application in large temporal-spatial turbulent magnetic reconnection. Part II. Role of turbulence in the flux rope interaction," Appl. Math. Modell. 78, 968-988 (2020); Wang and Zhu, "HIP-based heterogeneous parallel 3D LBM fluid simulator (HIP-LBM3D) V1.0 [software]," Patent No. 2023SR0533996 (6 March 2023); Zhu et al., "Scalable simulations of 3D turbulence fine structure in nanoflare using a novel plasma statistical algorithm," in Proceedings of the 5th International Conference on Statistics: Theory and Applications (ICSTA'23), 2023; Yan et al., "A new fluid numerical RHPIC-LBM algorithm from statistical physics," China Patent No. 202311118994.2; Wang et al., "HIP-based heterogeneous parallel 3D LBM HD simulator (HIP-HDLBM) V1.0 [software]," Patent No. 2023SR0533996. (March 6, 2023); Zhu et al., "Software development of GeV-level-SEPs-induced extreme space weather disasters with plasma statistical physics theoretical model on domestic DCU accelerator heterogeneous supercomputer." in Progress Report on China Nuclear Science &Technology: Computational Physics, 2024; Fu et al., "A new ARM-based CPU implementation of the RHPIC-LBM code," in 32nd General Assembly International Union, 2024; Wang and Zhu, "HIP-based heterogeneous parallel 3D LBM MHD simulator (HIP-MHDLBM) V1.0 [software]," No. 2024SR2094116 (December 16, 2024); Zhu and Wang, "Dynamic-magnetohydrodynamic-kinetic coupled algorithm for RHPIC-LBM code," China Patent No. 202511005823.8; Ma, "Fine-structure turbulence-induced dissipation-diffusion in the large temporal-spatial current sheet with mean field theory," M.S. thesis (School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing, China, 2025); Ma et al., "Fine-structure investigation of the turbulence-induced dissipation-diffusion in Flare-CME current sheets," Prog. Astron. 43(4), 1-26 (2025); Zhu et al., "Fine-structure investigation of turbulence-induced dissipation-diffusion in a nanoflare-loop with improved relativistic hybrid particle-in-cell and lattice Boltzmann method. I. Explicit expression and model," Phys. Fluids square, square (2025)], we validated, through simulations on a supercomputing platform, the basic features of turbulence and instabilities by considering anomalous viscosity and resistivity, and breaking of frozen-in condition. The simulation revealed that U-turbulence-induced viscosity dissipation-diffusion and B-turbulence-induced resistivity dissipation-diffusion interactions would lead to the following vortices/eddies-splitting and phase separating instabilities: (i) vortices/eddies-separation interface instabilities consisting of coupled B-Rayleigh-Taylor and U-Rayleigh-Taylor instabilities, and coupled B-Kelvin-Helmholtz and U-Kelvin-Helmholtz instabilities; (ii) twisted flux loop compression/expansion induced instabilities consisting of current/magnetic-driven multimode (m = 0, 1, 2, 3, 4......) Z- and {theta-pinch kink instabilities; and (iii) coupled B- and U-vortex shedding instabilities. This finding provides a comprehensive theoretical framework for elucidating the origins and sources of solar energetic particles (SEPs). It lays a pivotal foundation for clarifying the wave-particle interaction mechanisms responsible for extreme GeV-level SEP events, thereby facilitating the development of an early warning system for predicting SEP-induced space weather disasters.

In this work, the improved relativistic hybrid particle-in-cell & lattice Boltzmann method (RHPIC-LBM2), by adding multi-layer and the multi-component-abundance (M-CAI, Fe, Ni, electrons) module, is developed and applied to investigate the geomagnetic reversal on the supercomputer platform. Firstly, the explicit expression of the M-CAI terms under fully coupled hydro-dynamic-kinetic continuous scales was deduced by considering the turbulence-resistance-induced self-generated organization and the turbulence-viscosity-induced self-feeding-sustaining with dynamo mean field theory. Then, the input module was improved, and a new M-CAI module with the original RHPIC-LBM model algorithm code was added. Finally, the improved turbulence Debye-shielding model, which provides a way to describe the macro-dynamic averaging effect (2,200 kilometers) from numerous micro-kinematic (Debye length scale) evolutions, was used to explore the 2,200-kilometer-thick charged flow, current density, and magnetic field under fully coupled scale. The main findings of the present study are as follows: 1) the combined effect of buoyancy force (generated by mantle convection in the direction of the celestial axis; the convection from the heat of the inner core, outer core, and mantle), the centrifugal force-I (generated by the Earth rotates in the direction outward away from the celestial axis), the centrifugal force-II (generated by the earth revolution around the sun in the direction of Earth's axis of revolution, perpendicular to the ecliptic plane), the friction force-I (generated by the different velocity between the outer core and inner core in the tangential direction at the equatorial plane), the friction force-II(generated by the spin of the outer core and the mantel), the tidal force (generated by the gravitational attraction between the Earth and the moon); 2) the magnetic field will flap in 150~170 million years with 2~4 thousand years. These results may be a key point and give new insights for the investigation of the Earth-Moon space environment, which serves for the planetary environment research in 'National Mid- and Long-term Plan for Space Science in China (2024-2050) through the observational Earth magnetic model (Macao Science 1. WM3 real-time observational data).URL:分享文件：https://pan.cstcloud.cn/s/ftqeokDkRzc

Apatites and amphiboles are common hydrous minerals in igneous and metamorphic rocks, which can be found from the crust to the lithospheric mantle. These minerals can incorporate chlorine (Cl) and fluorine (F) by substituting for hydroxyl groups (OH). The isotopic compositions of Cl, Ca, and O of apatites and amphiboles are valuable geochemical tools for understanding the terrestrial and extraterrestrial processes over a wide range of temperatures. In the present study, first-principles methods were used to investigate the equilibrium isotope fractionation of Cl, Ca, and O in apatites and amphiboles. Our results reveal that amphiboles are generally more enriched in 37Cl compared to apatites. In apatites, increasing the Cl/(Cl + F) and Cl/(Cl + OH) ratios reduces the (1Cl-factors of Cl-F-apatites and Cl-OH-apatites, respectively, while substitution between F and OH has a small impact. In amphiboles, Cl contents have little effect on the (1Cl-factors. For Ca isotopes, the (1Ca-factors are largely unaffected by substitutions among Cl, F, and OH in either mineral. For O isotopes, the (1O-factors vary depending on the type of oxygen atoms. In Cl-F-apatites and Cl-OH-apatites, the (1O-factors for total oxygen atoms decrease with increasing Cl/(Cl + F) ratios but increase with Cl/(Cl + OH) ratios, respectively. Hydroxyl oxygen sites in amphiboles exhibit higher (1O-factors than those in apatites, whereas silicate oxygen sites are more enriched in 18O than phosphate oxygen sites. Correlations between bond lengths and isotope fractionation properties are also observed: in both apatites and amphiboles, the (1Cl-factor is negatively correlated with the Cl-Cation bond length, except in the cases of actinolite and richterite, while the (1O-factors of phosphate oxygen and silicate oxygen correlate with the O-P and O-Si bond lengths, respectively. These results can enhance our understanding of Cl, Ca, and O isotope behavior in halogen-bearing phosphates and silicates, providing valuable insights into the role of apatites and amphiboles as indicators of evolutionary processes on Earth and in extraterrestrial bodies.

Turbulence-induced dissipation-diffusion in fine-structures evolution is crucial for studying the energy translation process of nanoflare-loop large temporal–spatial turbulence magnetic reconnection. It is vital for resolving energy conversion between magnetic energy, acceleration energy (bulk kinetic energy), and heating energy (thermal kinetic energy) across different particle species (e.g., electron, ion, 3He, 4He, and other heavier particles) diffusion regions, which is key to understanding nanoflare heating and solar energetic particles' origin. As the first part of a two-paper series, in this study, we derived the explicit expression of turbulence-induced dissipation-diffusion terms under fully coupled hydrodynamics-magnetohydrodynamics-kinetic continuous scales by considering turbulence-resistance-induced self-organization and turbulence-viscosity-induced self-sustaining with filter theory. We enhanced the current relativistic hybrid particle-in-cell and lattice Boltzmann method by upgrading the input and dissipation-diffusion modules and adding a new turbulence-induced dissipation-diffusion module [B. J. Zhu et al., Appl. Math. Model. 78, 932–967 (2020); B. J. Zhu et al., Earth Planet. Phys. 3, 17–25 (2019); B. J. Zhu et al., Appl. Math. Model. 78, 968–988 (2020); W. Wang and B. J. Zhu, “HIP-based heterogeneous parallel 3D LBM fluid simulator (HIP-LBM3D) V1.0 [software],” No. 2023SR0533996, 2023; B. J. Zhu et al., “Scalable simulations of 3D turbulence fine structure in nanoflare using a novel plasma statistical algorithm,” in Proceedings of the 5th International Conference on Statistics: Theory and Applications (ICSTA'23) (2023), p. 122; H. Yan et al., “A new fluid numerical RHPIC-LBM algorithm from statistical physics,” China patent 202311118994.2; W. Wang et al., “HIP-based heterogeneous parallel 3D LBM HD simulator (HIPHDLBM) V1.0 [software],” No. 2023SR0533996, 2023; B. J. Zhu et al., “Software development of GeV-level-SEPs-induced extreme space weather disasters with plasma statistical physics theoretical model on domestic DCU accelerator heterogeneous supercomputer,” Prog. Rep. China Nucl. Sci. Technol.: Comput. Phys. 8, 1–40 (2024); Z. H. Fu et al., “A new ARM-based CPU implementation of the RHPIC-LBM code,” 32nd General Assembly Int. Union 197 (2024); W. Wang and B. J. Zhu, “HIP-based heterogeneous parallel 3D LBM MHD simulator (HIP-MHDLBM) V1.0 [software],” No. 2024SR2094116, 2024; B. J. Zhu and W. Wang, “Dynamic-magnetohydrodynamic-kinetic coupled algorithm for RHPIC-LBM code,” China patent 202511005823.8 (2025); Z. K. Ma, “Fine-structure turbulence-induced dissipation-diffusion in the large temporal-spatial current sheet with mean field theory,” M.S. thesis, University of Chinese Academy of Sciences, 2025; Z. K. Ma et al., “Fine-structure investigation of the turbulence-induced dissipation-diffusion in Flare-CME current sheets,” Prog. Astron. 43(4), 1–26 (2025)]. Anomalous U-turbulence-induced viscosity dissipation-diffusion and B-turbulence-induced resistivity dissipation-diffusion, which exceed their classical counterparts, lead to self-generated turbulence through interactions and feedback between U and B, resulting in two fully coupled dissipation processes. The explicit expression and model are applied to explore the turbulence evolution of magnetic- and current-rotational instabilities in Part II [B. J. Zhu et al., Phys. Fluid 37, 11 (2025)].

Olivine, typically occurring as a forsterite-fayalite solid solution, is a major rock-forming mineral in mafic and ultramafic igneous rocks, and it is important for understanding the genesis, evolution, and alteration of its host rocks. In this study, both GGA and GGA + U methods were employed to calculate the reduced partition function ratios of Fe, Mg, O, and Si isotopes for the forsterite-fayalite solid solution, aiming to elucidate the impacts of Fe content and Hubbard U correction on the isotope fractionation signatures of Fe, Mg, O, and Si in olivine. On the whole, the beta(Fe)-factor, beta(Mg)-factor, beta(O)-factor, and beta(Si)-factor decrease with increasing Fe content. The linear correlations between beta-factors and bond lengths obtained from GGA + U are better compared to those from GGA. The Hubbard U correction can increase the beta(Fe)-factor. When Fe/(Fe + Mg) <= 1/8, <= 1/2, and <= 1/2, the effect of Hubbard U correction on beta(Mg)-factor, beta(O)-factor, and beta(Si)-factor can be considered negligible, respectively, suggesting that the beta(Mg)-factor, beta(O)-factor, and beta(Si)-factor of Fe-bearing olivine calculated using GGA + U and those of Fe-free minerals calculated using GGA can be combined to derive 10(3)ln alpha and trace geological processes. Furthermore, equilibrium fractionation of Fe, Mg, O, and Si isotopes between olivine and other minerals, including troilite, clinopyroxene, and garnet, were also calculated. Our results are helpful in interpreting the observed data regarding Fe, Mg, O, and Si isotopic compositions of olivine, leading to a comprehensive understanding of relevant geological processes.

吸附是封存CO2的一种重要手段,也是降低CO2温室效应的一种有效途径.高岭石作为主要的黏土矿物,不仅具有较大的比表面积,而且分布广,封存CO2后不污染环境,是CO2的天然吸附剂.基于密度泛函理论的第一性原理计算CO2在高岭石(001)晶面的吸附,讨论吸附后的稳定构型、电子转移情况、密立根布居和分波态密度.结果表明在Top(1～3),Bridge(1～3)和Hollow(1～6)不同位点的吸附构型中,Hollow4-X构型最稳定,其吸附能为-0.41 eV.在Hollow4-X吸附构型中,CO2的O原子与晶面的H原子形成H—O键,其中CO2的O原子的2p轨道对成键贡献较大;高岭石(001)晶面H原子的电子转移到CO2的O原子上.

Isotope fractionation of zinc between Zn(H2O)62+, ZnCl(H2O)5+, ZnCl2(H2O)4, ZnCl3(H2O)−, ZnCl42−, ZnHCO3(H2O)3+, ZnCO3(H2O)3, Zn(OH)2(H2O)4, and ZnSO4(H2O)5 was explored by DFT method in this study, as well as the optimized structures, vibrational frequencies. These complexes were calculated by mixed basis sets LanL2DZ/6–311 + G(d, p) and def2-TZVP/6–311 + G(d, p). The results show that the optimized bond lengths calculated by mixed basis sets are more extensive than previous data, and the calculated vibrational frequencies are smaller than experimental values. Furthermore, the mixed basis sets lead to larger reduced partition function rations (RPFR) than 6–311 + G(d, p) basis set. Therefore, combining the calculated vibrational results with previous studies and experimental data, the def2-TZVP/6–311 + G(d, p) basis set may be more suitable for calculating Zn isotope fractionation.

The structures and the vibrational frequencies of complexes are basic parameters, and Cd (cadmium) is a crucial transition metal element in nature and their organic complexes are important for Cd transportation in organism systems. Here, we use the Gaussian 09 with forced symmetry to calculate the structures and the vibrational frequencies of selected Cd complexes. Our calculated results show that for Cd organic complexes, the calculated bond lengths of these complexes by the two methods (with and without forced symmetry) are almost the same, and though there exists a very small difference between the frequencies calculated by these two methods, the frequency difference of Cd isotope 110Cd and 114Cd is almost the same. Overall, with and without forced symmetry can be used to calculate these parameters of Cd complexes, but without using forced symmetry in the calculation is able to reduce the CPU time consumption and improve computational efficiency, especially for Cd organic complexes with more atoms.

Iron is the most important component of the cores of terrestrial planets, and iron sulfide (FeS) is one of the preferred candidates present in these cores. FeS is also ubiquitous in Earth's crust, peridotites, and extraterrestrial samples. Knowledge of the phase stability of FeS and Fe isotope fractionation between FeS phases and mantle silicates is of great importance for understanding the interior of the Earth and terrestrial planets. In this study, first-principles methods were used to study the pressure-dependent phase stability of FeS and equilibrium Fe isotope fractionation in FeS, hexagonal close-packed (hcp) Fe, and mantle silicates at the pressure of Earth's interior. FeS underwent four phase transitions at 0 K. The first is the transition from FeS I to FeS II at 2.8 GPa, the second from FeS II to FeS III at 7.5 GPa, the third from FeS III to FeS VI at 74.2 GPa, and the fourth from FeS VI to FeS VII at 122.2 GPa. Apart from the fact that the transition from FeS I to FeS II causes negligible Fe isotope fractionation, other phase transitions can cause measurable Fe isotope fractionation at corresponding pressures along the geotherm. Fe isotopes exhibit measurable fractionation between FeS and mantle silicates under mantle pressure-temperature conditions. Each phase was more enriched in heavy Fe with increasing depth in the pressure range of 7.5-90 GPa. If the silicate mantle is enriched in heavy Fe relative to the core or Fe has negligible isotope fractionation between them under the core-mantle boundary (CMB) conditions of the Earth, the Fe2+/(Fe2++Mg) in (Fe2+, Mg)SiO3 post-perovskite is less than 50%. At the temperature-pressure conditions of Earth's core, equilibrium Fe isotope fractionation between hcp Fe and FeS VII can be neglected. FeS III is more likely to exist in the Martian core relative to FeS VI. (c) 2022 Elsevier Ltd. All rights reserved.

Fe, Ni, and S isotopes are important chemical tracers, and they complement each other to improve our understanding of the Earth's evolution. As common accessory minerals in the Earth's interior and the most important group of ore minerals, sulfide minerals display a wide range of Fe and Ni contents. Using first-principles methods, we investigated the equilibrium fractionation factors of Fe, Ni, and S isotopes of the β-(Ni, Fe)S, FeS2-NiS2, and Fe3S4-Ni3S4 solid solutions, to constrain the effect of cation contents on Fe, Ni, and S isotopic signatures. For the β-(Ni, Fe)S solid solution, the iron β-factors, nickel β-factors, and sulfur β-factors all decrease approximately linearly with the increasing Fe content. For the FeS2-NiS2 solid solution, the iron β-factors, nickel β-factors, and sulfur β-factors show a positive linear relationship with the Fe content. For the Fe3S4-Ni3S4 solid solution, the iron β-factors and nickel β-factors have a strong negative correlation with the Fe content, while the sulfur β-factors have a weak negative correlation with the Fe content. In general, the trend of variation of the β-factors with Fe content is the opposite to that of the average bond lengths with the Fe content. Our results provide an improved understanding of Fe, Ni, and S isotopic fractionation in natural systems that may be used to better constrain physical, chemical, and geo-biological evolution on Earth.

Adsorption mineralization of gold is an important mineralization mechanism under epigenetic and low temperature conditions. In this paper, a plane-wave pseudopotential method based on density functional theory (DFT) is used to explore the adsorption mechanism of gold on the surface of pyrite. Among the three surfaces of pyrite, the surface energies of (100), (111), and (210) surfaces are 1.0508, 1.5337, and 1.8255 J∙m2, respectively, and the (100) surface is the most stable surface in the thermodynamic state. The adsorption capacities of gold atoms under different surfaces are (210) (−2.68 eV) > (111) (−1.67 eV) > (100) (−0.84 eV). Mulliken analysis indicates that charge transfer occurs after the adsorption of gold atoms onto the surface of pyrite (210), and gold and iron atoms are oxidized with the reduction of sulfur atoms. The density of states (PDOS) analysis shows that the 5d orbital on the Fermi energy level of the iron atom is active and the adsorption capacity is greater than that of the sulfur atom, and adsorption is formed between the gold atom, which leads to the gold being able to be stably deposited on the surface of pyrite (210).

Nickel sulfides are common in nature, and have been found in mantle-related rocks and xenoliths. Their properties exhibit significant differences with silicates in density, conductivity, and elasticity, and may be responsible for the geophysical anomalies in the upper mantle. Whether there is a difference in thermodynamic properties between sulfides and silicates in the upper mantle is not yet known. In the present study, the thermodynamic properties of millerite (NiS), heazlewoodite (Ni3S2), and polydymite (Ni3S4)-violarite (FeNi2S4) series with Fe/(Fe + Ni) = 0, 1/6 and 2/6 are calculated using the first-principles methods together with the quasi-harmonic approximation. The thermodynamics properties of some sulfides, including equation of state, isothermal bulk modulus, thermal expansion coefficient, heat capacity, and entropy are consistent with the available previous calculated and experimental data. The effect of Fe content on the thermodynamic properties of polydymite are also investigated, which show that with the increase of substitution Fe for Ni, the bulk modulus increases while the coefficient of thermal expansion decreases. Our calculations show that the coefficient of thermal expansion of Ni sulfides are higher than that of olivine and pyroxenes, while the adiabatic bulk modulus of Ni sulfides are lower than that of forsterite.

Cu在自然界主要以硫化物的形式存在,目前只确定了几种含Cu硫化物的S同位素分馏系数以及黄铜矿的Fe同位素分馏系数,而且不同研究者确定的系数有很大的差别,使得S、Fe同位素在研究铜矿床的形成、演化等方面不能很好地发挥示踪作用.因此,本文基于第一性原理计算确定了0～1 000℃温度范围内主要含Cu硫化物的S同位素简约配分函数比(103lnβ34-32),以及Cu-Fe硫化物的Fe同位素简约配分函数比(103lnβ57-54).重S同位素在这些含Cu硫化物中的富集顺序为铜蓝＞方黄铜矿＞黄铜矿≈黑硫铜镍矿＞斑铜矿＞辉铜矿,重Fe同位素在Cu-Fe硫化物中的富集顺序为方黄铜矿≈黄铜矿＞低温斑铜矿＞高温斑铜矿＞中温斑铜矿＞Cu8Fe4S8(中温斑铜矿的可能变体).含Cu硫化物的103lnβ34-32与S原子的配位数、金属-S平均键长、S原子形成的所有化学键的平均键长没有明显的相关性,而Cu-Fe硫化物的103lnβ57-54与Fe—S平均键长基本成线性负相关关系.辉铜矿相变引起的S同位素分馏特别大,而斑铜矿相变时产生的S同位素分馏却可以忽略不计.本文的计算结果将会为探讨斑岩铜矿及其它类型的硫化物矿床的成因提供支持.

Nickel sulfide minerals, an important type of metal sulfides, are the major component of mantle sulfides. They are also one of the important windows for mantle partial melting, mantle metasomatism, and mantle fluid mineralization. The elasticity plays an important role in understanding the deformation and elastic wave propagation of minerals, and it is the key parameter for interpreting seismic wave velocity in terms of the composition of the Earth’s interior. Based on first-principles methods, the crystal structure, equation of state, elastic constants, elastic modulus, mechanical stability, elastic anisotropy, and elastic wave velocity of millerite (NiS), heazlewoodite (Ni3S2), and polydymite (Ni3S4) under high pressure are investigated. Our calculated results show that the crystal structures of these Ni sulfides are well predicted. These Ni sulfides are mechanically stable under the high pressure of the upper mantle. The elastic constants show different changing trends with increasing pressure. The bulk modulus of these Ni sulfides increases linearly with pressure, whereas shear modulus is less sensitive to pressure. The universal elastic anisotropic index AU also shows different changing trends with pressure. Furthermore, the elastic wave velocities of Ni sulfides are much lower than those of olivine and enstatite.

With high porosity and being one of the most abundant clay minerals, dried kaolinite may be an excellent adsorbent to remove ammonia gas (NH3). Here, the plane wave pseudopotential method based on density functional theory (DFT) was used to explore the mechanism of ammonia gas adsorption on the dried kaolinite, the Mulliken electric charge, and the partial density of states of atoms of the NH3/kaolinite (001) system. NH3 adsorption on kaolinite can happen in three different type adsorption positions: “top”, “bridge” and “hollow”. The “hollow” position is enclosed by two "upright" hydroxyl groups perpendicular to the (001) surface of kaolinite and a "lying" hydroxyl group parallel to the surface. At this position, the adsorption is the most stable and has the highest adsorption energy. The nitrogen atom of the NH3 molecule bonds with the hydrogen atom in the "upright" hydroxyl group on the (001) surface and its hydrogen atom forms HN…O hydrogen bond with oxygen atom in the "lying" hydroxyl group, which leads to the NH3 stably adsorbed on kaolinite (001) surface. A small part of electrons transfer between NH3 molecules and kaolinite creates weakly electrostatic adsorption between them.