A few basic concepts in crystal Theory Unit Cells The basic repeating unit of a crystalline solid.Any of the unit cells,when repeated in space in all three dimensions,forms t the lattice structure characteristic of a crystalline solid. The essentials of unit cells: 1.unit cell dimension and shape: cell parameters:a,b,c, and a,B, a,b,c为六面体边长，a, b B,y分别是bc,ca,b所 a y 组成的夹角。 XUnit Cells ： The basic repeating unit of a crystalline solid. Any of the unit cells, when repeated in space in all three dimensions, forms the lattice structure characteristic of a crystalline solid. cell parameters: a，b，c， and α，β，γ. a，b，c 为六面体边长， α， β，γ 分别是bc ， ca , ab 所 组成的夹角。 The essentials of unit cells： 1. unit cell dimension and shape： A few basic concepts in crystal Theory