习题2解答
1、立方点阵单胞轴长为a，给出简单立方、体心立方、面心立方这三种点阵的每一个阵点的最近邻、次近邻的点数，求出最近邻、次近邻的距离。
2、某正交晶系单胞中，在如下位置有单原子存在：①(0, 1/2, 0)，(1/2, 0, 1/2)两种位置都是同类原子；②([1/2, 0,0])，(0, 1/2, 1/2)上是A 原子，(0, 0, 1/2)，(1/2, 1/2, 0)是B 原子。问上两种晶胞各属于哪一种布喇菲点阵？
3、Fig.1 shows a unit cell of a hypothetical metal. (a) To which crystal system does this unit cell belong? (b) What would this crystal structure be called? (c) Calculate the density of the material, given that its atomic weight is 141 g/mol.
Fig.1 体心正方，
Fig. 2
=8.5×103
4、The unit cell for uranium has orthorhombic symmetry, with a, b, and c lattice parameters of 0.286, 0.587 and 0.495 nm, respectively. If its density, atomic weight, and atomic radius are 19.05 g/cm3, 238.03 g/mol, and 0.1385 nm, respectively, compute the atomic packing factor（APF）.
=0.536
5、Three different crystallographic planes for a unit cell of a hypothetical metal are shown in Fig.2. The circles represent atoms. (a) To what crystal system does the unit cell belong? (b) What would this crystal structure be called? (c) If the density of this metal is 18.91 g/cm3, determine its atomic weight. 正交，面心正交，42.7g/mol
材料科学基础 习题2答案
