rhombohedral

The team carried out some simple calculations and found that some coordinated behavior among electrons should emerge in a structure of five graphene layers stacked together in a rhombohedral pattern.

More specifically, lead titanate changes shape from tetragonal to rhombohedral through monoclinic intermediates under pressure.

Those with a triad axis are grouped together in the rhombohedral or trigonal division, and those with a hexad axis in the hexagonal division.

The habit of the crystals may be rhombohedral, pyramidal or tabular, rarely prismatic.

GRAPHITE, a mineral species consisting of the element carbon crystallized in the rhombohedral system.