trigonal system

trigonal system

[trī′gōn·əl ′sis·təm]
(crystallography)
A crystal system which is characterized by threefold symmetry, and which is usually considered as part of the hexagonal system since the lattice may be either hexagonal or rhombohedral.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
1 show that all the peaks coincide with those of calcite containing magnesium (Ca, Mg)CO3 (JCPDS 43-0697), which is indexed in the trigonal system with the R-3c space group (No.
This is Renault's trigonal system that is mounted on a sub frame away from the main body and insulates the interior from road noise.