Mikuła A, Król M, Koleżyński A
Department of Silicate Chemistry and Macromolecular Compounds, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, 30 Mickiewicza Av., 30-059, Krakow, Poland.
J Mol Model. 2015 Oct;21(10):275. doi: 10.1007/s00894-015-2820-0. Epub 2015 Oct 1.
Zeolites are a group of microporous aluminosilicate frameworks with numerous applications in, for example, catalysis and ion-exchange and sorption processes. One of the most important tools for analyzing the properties of zeolite structures is vibrational spectroscopy. However, the complexity of these structures often leads to difficulties when attempting to interpret the resulting spectra, so an additional complementary tool is required: computational methods. The aim of this study was to formulate a simplified periodic model of an LTA framework containing alkali metal cations (either Li(+), Na(+), K(+), Rb(+), or Cs(+)) and to perform a set of ab initio calculations aimed at assessing the influence of these cations on the properties of the vibrational spectra of the LTA framework. Additionally, chemical bonding was analyzed by means of electron density topology analysis. Results obtained were compared with experimental spectra for alkali metal forms of zeolite A. It was found that the vibrational spectra obtained using the proposed model agree well with the corresponding experimentally derived spectra, meaning that the model can be used to analyze real spectra in detail.
沸石是一类微孔铝硅酸盐骨架，在催化、离子交换和吸附过程等众多领域都有应用。分析沸石结构性质的最重要工具之一是振动光谱学。然而，这些结构的复杂性在试图解释所得光谱时常常导致困难，因此需要一种额外的补充工具：计算方法。本研究的目的是构建一个包含碱金属阳离子（Li⁺、Na⁺、K⁺、Rb⁺或Cs⁺）的LTA骨架的简化周期性模型，并进行一组从头算计算，旨在评估这些阳离子对LTA骨架振动光谱性质的影响。此外，通过电子密度拓扑分析对化学键进行了分析。将所得结果与A型沸石碱金属形式的实验光谱进行了比较。结果发现，使用所提出的模型获得的振动光谱与相应的实验衍生光谱吻合良好，这意味着该模型可用于详细分析实际光谱。
