Color Groups Associated with Square and Hexagonal Lattices
In this paper, we obtain the list of all color groups associated with a coloring of a square or hexagonal lattice Λ arising from sublattices of Λ. The results are obtained using a canonical representation of a sublattice L of Λ by a 2 × 2 matrix and no restriction on whether L is compatible or not with Λ is imposed.
de Las Peñas, M. L. A. N., & Felix, R. P. (2007). Color groups associated with square and hexagonal lattices. Zeitschrift für Kristallographie, 222(10), 505-512.