Periodic Hartree-Fock study of minerals; hexacoordinated SiO 2 and GeO 2 polymorphs
Periodic Hartree-Fock study of minerals; hexacoordinated SiO 2 and GeO 2 polymorphs
复制标题
定期进行 Hartree-Fock 矿物研究；
DOI：
10.1127/ejm/6/1/0007
复制
发表时间：
1994
影响因子：
2.1
通讯作者：
P. D'arco
中科院分区：
文献类型：
--
作者：
Luc;B. Silvi;P. D'arco
采用周期Hartree-Fock方法研究了sio2和geo2的金红石结构以及另外三种假定的六配位晶型（锐钛矿、黄铁矿和α-PbO - 2）的结构和稳定性。为此目的设计了一个通用的基础集，允许对二氧化硅和镁硅酸盐进行精确计算。报道了这四种晶型的优化结构参数和状态方程系数。金红石结构的计算值与现有的实验数据吻合较好。计算得到的状态方程表明，在0 ~ 200gpa压力范围内，sio2只有stishovite相稳定，而在60gpa压力范围内，Pbcn和Pa3对称相稳定
The structure and stability of the rutile structure of SiO 2 and GeO 2 and of three other putative hexacoordinated polymorphs, namely the anatase, pyrite and α-PbO 2 structures, have been investigated by the Periodic Hartree-Fock method. A universal basis set allowing accurate calculations on both silica and magnesiosilicates has been designed for this purpose. The optimized structural parameters and equation-of-state coefficients of these four polymorphs are reported. The calculated values for the rutile structure are in good agreement with the available experimental data. It is shown from the calculated equations of state that, for SiO 2 , only the stishovite phase is stable in the 0-200 GPa pressure range, whereas, for GeO 2 , the phases with Pbcn and Pa3 symmetry become stable above 60 GPa