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在一个大气压和53千巴之间的五个压力条件下所做的透辉石高压结构研究表明,组成结构的 M(1),M(2)和 Si 三种多面体的大小呈现出不规则的缩小.M(1)和 M(2)多面体的体积约缩小5%,而 Si 多面体的体积仅缩小1%.透辉石和深绿辉石(另一种单斜辉石)的高压结构变化的对比表明,两者具有显著的差异,透辉石的四面体和 M(1)多面体压缩较小,而硅酸盐链的折曲程度较大;透辉石单位晶胞参数的变化为:在一个大气压下,a=9.7456(7).b=8.9198(8).c=5.2516(5)A 和β=105.86(1).到53.0干巴压力时,a=9.612(2),b=8.765(1).c=5.1793(2)A 和β=105.32(1).压力的增高对相等的均匀温度因子的影响极小.某些结构特征[〈M(1)—O〉,〈M(2)—O〉.O(3)—Si—O(3)和 O(3)—O(3)—O(3)]随着由于 T 或 P 引起单位晶胞体积的变化,显示“相反”变化的特性,而其它结构特征(晶胞参数β和〈Si—O〉)则不显示出这种变化.根据 P—V 数值按 Birch—Murnaghan 状态方程加权拟合计算出的总模量及其压力导数分别是1.14(4)毫巴和4.5(1.8)。结构的压缩率受 M(1)和 M(2)键的控制.牢固的 M—O 键平行于最小的可压缩方向(∈_1),而最大的可压缩 M—O 键方向垂直于(∈_1),并介于两个最大可压缩方向∈_2和∈_3之间,近似45°.
Studies on the diopside high-pressure structure at five pressures between 53 bar and 53 bar show that the sizes of the three polyhedrons of M (1), M (2) and Si are irregular The volume of the M (1) and M (2) polyhedrons is reduced by about 5%, while the volume of the Si polyhedron is only reduced by 1%. The high pressure structure of diopside and pyroxene (the other clinopyroxene) The comparison shows that there is a significant difference between them. The dihedral and M (1) polyhedrons of diopside are less compressed and the degree of bending of silicate chains is larger. The unit cell parameters of diopside are changed as follows: A = 9.7456 (7) .b = 8.9198 (8) .c = 5.2516 (5) A and β = 105.86 (1) 1) .c = 5.1793 (2) A and β = 105.32 (1). The effect of pressure on the equal uniform temperature is minimal. Some structural features [, O (3) -Si-O (3) and O (3) -O (3) -O (3)] show “opposite” as the unit cell volume changes due to T or P, , While other structural features (unit cell parameters β and ) do not show this change.According to the P-V values according to Birch -Murnaghan Equation of State Weighted Fit The calculated total modulus and its pressure derivative are 1.14 (4) mbar and 4.5 (1.8), respectively. The compressibility of the structure is governed by the M (1) and M (2) bonds which are parallel to the smallest compressible direction (∈_1) and the largest compressible M-O bond is perpendicular to (∈ _1) and lies between two largest compressible directions ∈_2 and ∈_3, approximately 45 °.