A triangular lattice is a two-dimensional point lattice generated by two vectors of equal length
meeting at an angle of 
. It is the root lattice 
up to scale and rotation,
and is the set of vertices
of a triangular grid. Its Voronoi
cells are regular hexagons, so the same point lattice is sometimes called a hexagonal
lattice in packing contexts.
Triangular Lattice
See also
Brillouin Zone, Circle Packing, Hexagonal Grid, Hexagonal Lattice, Point Lattice, Root Lattice, Triangular GridExplore with Wolfram|Alpha
References
Nebe, G. and Sloane, N. J. A. "The Lattice A2." Catalogue of Lattices. Jul. 18, 2014. https://www.math.rwth-aachen.de/~Gabriele.Nebe/LATTICES/A2.html.Cite this as:
Weisstein, Eric W. "Triangular Lattice." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/TriangularLattice.html