rhomboedral
Rhomboedral, often spelled rhombohedral in modern usage, is an adjective used in geometry and crystallography to describe a shape or lattice based on a rhombohedron. A rhombohedron is a six-faced polyhedron whose faces are congruent rhombi; all edges are of equal length, and opposite faces are parallel. It is a type of parallelepiped and can be formed by skewing a cube along a body diagonal. The angles between edges are not right angles, and the dihedral angles between adjacent faces are generally oblique.
In geometry, the rhombohedron is a common example of a solid with equal edge lengths but non-orthogonal
In crystallography, rhombohedral refers to crystals whose lattice or unit cell can be described as a rhombohedron.