From Online Dictionary of Crystallography
Revision as of 16:02, 7 December 2017 by MassimoNespolo (Lang (Ar))
متكافئ أو متجانس الزوايا (Ar). Isogonal (Fr). Isogonal (Ge). Isogonale (It). 等角の (Ja). Изогональная (Ru). Isogonal (Sp).
Isogonal is a mathematical term which means having similar angles. In geometry, a polytope is isogonal or vertex-transitive if all its vertices are equivalent, i.e. if each vertex is surrounded by the same kinds of face in the same or reverse order, and with the same angles between corresponding faces.
In crystallography, the term isogonal has been introduced by Buerger to indicate isometries characterized by the same (proper or improper) rotation part and different translation parts. In other terms, isogonal isometries have the same matrix part but different vector parts. The term isogonal was also used to indicate space groups belonging to the same geometric crystal class.
- Buerger, M.J. (1956). Elementary crystallography. New York, Wiley.