▎ 摘　　要

The graphene plane possesses a high hexagonal symmetry. Currently, it is largely studied as 2D crystal, especially due to its very interesting potential electronic properties. It is also frequently studied in the 3D stackings as graphite. When a layer of a chemical species is dropped off on a graphene layer, it is common to observe a right adaptation between both 2D crystal networks. This commensurability is consistently studied in this paper by means of a mathematical approach. Through this method, it has been possible to take an inventory of all 2D unit cells commensurate with hexagonal graphene cell. Hexagonal, rectangular and oblique cells can be perfectly listed for the different values of the number of carbon atoms included in the cell. Numerous experimental examples are given in the field of graphite intercalation compounds. And very especially the graphite-electron donors lamellar compounds have been used in order to illustrate the method and its results. (C) 2015 Elsevier Ltd. All rights reserved.