rotation-inversion axis
[roh-tey-shuh n in-vur-zhuh n, -shuh n]
noun Crystallography.
an axis of a crystal such that rotating about the axis and then inverting the crystal brings the crystal back to its original position.
Compare symmetry element.
Also called symmetry axis of rotary inversion.
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Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019