MgCO $_3$ - CaCO $_3$ -Li $_2$ CO $_3$ -Na $_2$ CO $_3$ -K $_2$ CO $_3$碳酸盐熔体：热力学和输运性质的原子模拟
The MgCO$_3$-CaCO$_3$-Li$_2$CO$_3$-Na$_2$CO$_3$-K$_2$CO$_3$ Carbonate Melts: Thermodynamics and Transport Properties by Atomistic Simulations
摘要：
原子模拟提供了一种有意义的方法来确定液体的物理化学性质在一个一致的理论框架。这种方法对熔融碳酸盐的研究特别有用，在热力学和运输数据是至关重要的需要在一个大的域的温度和压力（以确定这些熔体在地球化学过程中的作用）的背景下，但在文献中是非常稀缺的，特别是在地球的地幔中占主导地位的钙镁成分。在我们对Li_2CO_3-Na_2CO_3-K_2CO_3熔体的研究之后，我们将我们的力场扩展到Ca和Mg组分。经验相互作用势基准上的密度数据，在实验文献中（晶体和K2 Ca（CO 3）2熔体）和从从头计算分子动力学模拟发出的液体结构。在此基础上，采用分子动力学模拟研究了含Ca、Mg碳酸盐熔体在2073 K和15 GPa下的热力学、微观结构、扩散系数、电导率和粘度。此外，状态方程的Na-Ca-K混合物代表的熔岩发射在Ol Doinyo Lengai（坦桑尼亚）的评价。MD结果与现有实验数据之间的总体一致性非常令人满意，并且为力场在大的T-P范围内精确模拟任何MgCO 3-CaCO 3-Li 2CO 3-Na 2CO 3-K2 CO 3熔体的能力提供了证据。此外，这是第一次报告的力场允许研究熔融菱镁矿（MgCO 3）和熔融白云石（CaMg（CO 3）2）的传输特性。
英文摘要：
Atomistic simulations provide a meaningful way to determine the physico-chemical properties of liquids in a consistent theoretical framework. This approach takes on particular usefulness for the study of molten carbonates, in a context where thermodynamic and transport data are crucially needed over a large domain of temperatures and pressures (to ascertain the role of these melts in geochemical processes) but are very scarce in the literature, especially for the calco-magnesian compositions prevailing in the Earth's mantle. Following our work on Li2CO3-Na2CO3-K2CO3 melts, we extend our force field to incorporate Ca and Mg components. The empirical interaction potentials are benchmarked on the density data available in the experimental literature (for the crystals and the K2Ca(CO3)2 melt) and on the liquid structure issued from ab initio molecular dynamics simulations. Molecular dynamics simulations are then performed to study the thermodynamics, the microscopic structure, the diffusion coefficients, the electrical conductivity and the viscosity of molten Ca, Mg-bearing carbonates up to 2073 K and 15 GPa. Additionally, the equation of state of a Na-Ca-K mixture representative of the lavas emitted at Ol Doinyo Lengai (Tanzania) is evaluated. The overall agreement between the MD results and the existing experimental data is very satisfying and provides evidence for the ability of the force field to accurately model any MgCO3-CaCO3-Li2CO3-Na2CO3-K2CO3 melt over a large T - P range. Moreover it is the first report of a force field allowing to study the transport properties of molten magnesite (MgCO3) and molten dolomite (CaMg(CO3)2).
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
