rotation-reflection axis

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rotation-reflection axis

[rō′tā·shən ri′flek·shən ‚ak·səs]
(crystallography)
A symmetry element of certain crystals in which a crystal can be brought into a position physically indistinguishable from its original position by a rotation through an angle of 360°/ n about the axis followed by a reflection in the plane perpendicular to the axis, where n is the multiplicity of the axis, equal to 1, 2, 3, 4, or 6.
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