What's the difference between hemihedral and holohedral?
Hemihedral
Definition:
(a.) Having half of the similar parts of a crystals, instead of all; consisting of half the planes which full symmetry would require, as when a cube has planes only on half of its eight solid angles, or one plane out of a pair on each of its edges; or as in the case of a tetrahedron, which is hemihedral to an octahedron, it being contained under four of the planes of an octahedron.
Example Sentences:
(1) The statistics of intensity data from hemihedrally twinned specimens are analyzed in terms of a new parameter and are shown to take a simple form in both the centrosymmetric and non-centrosymmetric cases.
Holohedral
Definition:
(a.) Having all the planes required by complete symmetry, -- in opposition to hemihedral.