Faculty of Physics, West University of Timisoara, V. Parvan 4, Timisoara, 300223, Romania.
CNRS, CRM2, Université de Lorraine, Nancy, F-54000, France.
Acta Crystallogr B Struct Sci Cryst Eng Mater. 2020 Oct 1;76(Pt 5):749-756. doi: 10.1107/S2052520620009002. Epub 2020 Aug 13.
The present paper reports a theoretical investigation based on first-principles density functional theory calculations to predict the external morphology of the tetragonal GdVO crystal from its internal structure. The Bravais-Friedel-Donnay-Harker (BFDH) method, attachment energy (AE) method and surface energy (SE) method were used in this study. Slice energies (cohesive, attachment and specific surface) of the three main crystal faces having (110), (101) and (200) orientation and their d thicknesses were computed using CRYSTAL17 code, in the frame of a 2D periodic slab model. The relative growth rate (R) and the morphological importance (MI) for each unrelaxed and relaxed (hkl) face of interest were determined. Consequently, the crystal shapes predicted based upon BFDH, AE and SE methods were represented by the Wulff construction. The results of the morphology crystal predictions, based on the above methods, were compared both against each other and against the experimentally observed morphologies. A quite satisfactory agreement between the predicted and observed crystal morphologies is noticed.
本文基于第一性原理密度泛函理论计算，通过布拉维-弗里德尔-唐纳-哈克（Bravais-Friedel-Donnay-Harker，BFDH）法、附着能（attachment energy，AE）法和表面能（surface energy，SE）法，对四方相 GdVO 晶体的外部形态与其内部结构进行预测。采用 CRYSTAL17 代码，在二维周期性平板模型框架下，对具有（110）、（101）和（200）取向的三个主要晶面的体能（内聚能、附着能和比表面能）以及它们的 d 厚度进行了计算。通过计算，确定了各未弛豫和弛豫（hkl）面的相对生长速率（relative growth rate，R）和形态重要性（morphological importance，MI）。然后，根据 BFDH、AE 和 SE 方法，通过沃尔夫构造法对晶体形状进行了预测。基于上述方法的晶体形态预测结果，与实验观察到的形态进行了比较。结果表明，预测的晶体形态与实验观察到的形态之间存在较好的一致性。
