点计metallic crystals packing ef

发布网友发布时间：2023-09-14 15:43

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热心网友时间：2023-09-14 18:25

更新1:

Hexagonal close-packing: 74.1% 呢?

Packing efficiency =volume of spheres in unit cell / volume of unit cell = no. of atom in unit cell X(volume of sphere) / (edge length)^3 For simple cubic packing : Edge length = 2r no of atom in unit cell = 1 Packing efficiency = (1X(4/3πr^3)/(2r)^3) X 100% = 52.4% For body centered cubic : Edge length = 4r/ 图片参考：upload.wikimedia/math/1/6/0/160a5b4ac79375bd4c5e13c0f3a95f73 3 no of atom in unit cell = 1 Packing efficiency = (2X(4/3πr^3)/(4r/ 图片参考：upload.wikimedia/math/1/6/0/160a5b4ac79375bd4c5e13c0f3a95f73 3)^3) X 100% = 68% For face center cubic : Edge length = 图片参考：upload.wikimedia/math/1/6/0/160a5b4ac79375bd4c5e13c0f3a95f73 8 X r no of atom in unit cell = 4 Packing efficiency = (4X(4/3πr^3)/( 图片参考：upload.wikimedia/math/1/6/0/160a5b4ac79375bd4c5e13c0f3a95f73 8 X r)^3) X 100% =74%
这只是大约　没有一定如果要计算，你只要在晶胞中找　原子／离子的半径计算它们所占的体积，再利用原子数目　丫佛加得罗常数　密度　找晶胞体积它们所占的体积／晶胞体积　就是packing efficiency