Koudelka Bohdan, Capkova Pavla
Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University Prague, Ke Karlovu 3, 121 16 Prague 2, Czech Republic.
J Mol Model. 2002 May;8(5):184-90. doi: 10.1007/s00894-002-0085-x.
A method of structure analysis of intercalates has been developed that uses a combination of molecular simulations with powder diffraction. The program Supramol for the determination of intercalated structures uses crystal energy minimization in conjunction with powder diffraction data. The program solves the multiple minima problem in molecular mechanics, generating initial models systematically and searching for the global energy minimum by comparing the experimental and calculated diffraction patterns. The program is compatible with the Cerius2 modeling environment. Two intercalated crystal structures solved by Supramol are presented in the present paper: vanadyl phosphate intercalated with p-benzoquinone and the high temperature phase of vanadyl phosphate intercalated with dioxane. The structure of vanadyl phosphate intercalated with p-benzochinone is tetragonal, space group I4/ m, the unit cell parameters a=6.21 A, b=6.21 A, c=20.18 A and the density is rho=2.30 g x cm(-3), Z=4. The crystal structure of vanadyl phosphate intercalated with dioxane (high temperature phase) is monoclinic, space group C2/ m, unit cell parameters are: a= b=8.94 A, c=8.22 A, alpha=gamma=90 degrees, beta=106.30 degrees, Z=4, density 2.248 g x cm(-3).
已开发出一种嵌入物结构分析方法，该方法结合了分子模拟与粉末衍射。用于确定嵌入结构的Supramol程序结合粉末衍射数据使用晶体能量最小化。该程序解决了分子力学中的多个极小值问题，系统地生成初始模型，并通过比较实验和计算的衍射图谱来寻找全局能量最小值。该程序与Cerius2建模环境兼容。本文展示了由Supramol解析的两种嵌入晶体结构：对苯醌嵌入的磷酸氧钒以及二氧六环嵌入的磷酸氧钒高温相。对苯醌嵌入的磷酸氧钒结构为四方晶系，空间群I4/ m，晶胞参数a = 6.21 Å，b = 6.21 Å，c = 20.18 Å，密度ρ = 2.30 g·cm⁻³，Z = 4。二氧六环嵌入的磷酸氧钒（高温相）晶体结构为单斜晶系，空间群C2/ m，晶胞参数为：a = b = 8.94 Å，c = 8.22 Å，α = γ = 90°，β = 106.30°，Z = 4，密度2.248 g·cm⁻³。
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