Diopside (CaMgSi2O6\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$CaMgSi_{2}O_{6}$$\end{document}), the Ca- and Mg-rich clinopyroxene is an important mineral in the Earth’s upper mantle and subducted lithospheric plate. Here, we report the results of high-pressure single-crystal X-ray diffraction experiments conducted on a natural aluminous iron-bearing diopside and a natural, nearly end-member diopside, up to 50 GPa in diamond anvil cell. Density functional theory calculation results on end-member diopside are also reported. Unit cell parameters a, b, c, β\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\beta$$\end{document}, V, as well as bond lengths of diopside are reported and compared with other clinopyroxenes. Bulk modulus and its pressure derivative of the two diopside samples are determined using third-order Birch–Murnaghan equation of state. The density of the two diopside samples is calculated under cold subducting slab conditions and is compared with the seismic models. Along the cold slab geotherm, aluminous iron-bearing diopside has higher density than end-member diopside. In the upper mantle, eclogite with aluminous iron-bearing diopside is denser than eclogite with end-member diopside, and, therefore, provides larger slab pulling force. At the bottom of the transition zone and the top of the lower mantle, eclogite with aluminous iron-bearing diopside, though higher in density than the end-member diopside, is still less dense than the surrounding mantle and could contribute to the slab stagnation.

中文翻译：

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基于单晶 X 射线衍射和第一性原理计算的端元和含铝铁透辉石在高压下的压缩行为

透辉石 (CaMgSi2O6\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\ oddsidemargin}{-69pt}\begin{document}$$CaMgSi_{2}O_{6}$$\end{document})，富含钙和镁的单斜辉石是地球上地幔和俯冲岩石圈中的重要矿物盘子。在这里，我们报告了对天然含铝铁透辉石和天然近端元透辉石进行的高压单晶 X 射线衍射实验结果，金刚石砧座中高达 50 GPa。还报告了端元透辉石的密度泛函理论计算结果。晶胞参数 a, b, c, β\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin} {-69pt} \begin{document}$$\beta$$\end{document}、V 以及透辉石的键长被报告并与其他单斜辉石进行比较。使用三阶 Birch-Murnaghan 状态方程确定两个透辉石样品的体积模量及其压力导数。在冷俯冲板条条件下计算了两个透辉石样本的密度，并与地震模型进行了比较。沿冷板坯地热，含铝铁透辉石的密度高于端元透辉石。在上地幔中，含铝铁透辉石的榴辉岩比含端元透辉石的榴辉岩密度更大，因此，提供更大的板坯拉力。在过渡带底部和下地幔顶部，含铝铁透辉石的榴辉岩虽然密度高于端元透辉石，但密度仍低于周围地幔，可能导致板片停滞。