1.Hexagonal close-packing:(hep) Each third-layer sphere is directly over a first-layer sphere.The layers repeat in their pattern in the manner ABAB... Coordination number((配位数)：12 Spatial occupancy factor(空间占有率)74.05%（自己计算 1.Hexagonal close-packing: (hcp) Each third-layer sphere is directly over a first-layer sphere. The layers repeat in their pattern in the manner ABAB… Coordination number(配位数)：12 Spatial occupancy factor (空间占有率):74.05%(自己计算)