极性晶体结晶习性的形成机理

将负离子配位多面体生长基元模型应用于对极性晶体结晶习性的研究。从结晶化学角度探讨了晶体中负离子配位多面体的结晶方位与晶体各族晶面显露规律，提出负离子配位多面体在晶体各族晶面上联结的稳定性决定了晶面的生长速率。在不同的生长温度和溶液碱浓度下，负离子配住多面体相互联结构成不同维度的生长基元，而不同维度的生长基元往晶体各族晶面上叠合的速率比例是在变化的，这是导致晶体结晶形态多变性的主要原因。同时提出：如果把PBC模型中的化学键链设定为配位多面体相联结的键链，使得极性晶体结晶习性中难以解释的问题就会迎刃而解，从而使PBC理论模型的应用会得到更进一步的拓宽。

The crystal Habits and Formation Mechanism of Polar crystal

The theoretic model of the growth units of anionic coordination polyhedra is applied to studythe crystal habits of some poar crystals in this paper. From the analysis of the appearance regu-larities of different groups of faces with relation to the crystallographic direction of the anionic co-ordination polyhedra of the crystals by the viewpoint of crystal chemistry, it was proPosed thatthe growth rates of various faces are determined by the stability of the attachment of the anioniccoordinatbo Polyhedra on the different groups of faces. The anionic coordination poyhedra willassociate each other to form growth units with different dimensions depending on the growthtemperature and alkaline concentrations. The main reason for the morphology varieties of growncrystals is that the ratio of growth rates on various faces changs with various dimensions of thegrowth units incorporated in these faces. It is also suggested if the periedic bond chains in PBCtheory are considered as the chains of anionic coordination polyhedra, the crystal habits of Polarcrystals which were difficult to comprehend can easily be illustrated and the applications of PBCtheory can be extended more than ever be fore.