Hermann-Mauguin symbols

Hermann-Mauguin symbols

[′her·män ′mō‚gan ‚sim·bəlz]
(crystallography)
Symbols representing the 32 symmetry classes, consisting of series of numbers giving the multiplicity of symmetry axes in descending order, with other symbols indicating inversion axes and mirror planes.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.