Gallium(II) Selenide (GaSe)
The gallium(II) selenide structure adopts a hexagonal lattice with a fourteen-atom basis.
Views of a single unit cell
The structure below is an equivalent representation of a single unit cell of GaSe. Each unit cell contains ten Ga and four Se atoms. However, visualizing some of the atoms in the neighboring unit cell conveys a better understanding of the crystal structure. In these structures, Ga is purple and Se is orange.
Views of Multiple Unit Cells
The GaSe crystal structure can be generated by periodically reproducing the unit cell. Below are shown a block of 50 (5x5x2) and 1,125 (15x15x5) unit cells. In this structures below, the crystal is oriented so that the computer monitor is parallel to the (001) plane.
Views of Multiple Unit Cells
Crystal structures of arbitrarily large size can be constructed.
Crystal Structure Layers (on edge)
Seen in the (110) plane, one clearly observes the layered structure of the crystal.
Crystal Structure Layers (from top)
Seen in the (001) plane, one clearly observes that the triangular arrangement of the atoms in each layers.
Single Layers
In these structures below, only a single slab of atoms of Ga (left) or Se (right) are shown in the (001) plane.
References
Sickafus, K. E. et al. Layered Atom Arrangements in Complex Materials, A Technical Report from Los Alamos National Laboratory, Los Alamos, New Mexico, LA-14205, April 2006. posted: April, 2015.
updated: April, 2015.