R4×4n

R4×4n is a type of crystal structure belonging to the orthorhombic crystal system. In this structure, a fourfold rotation axis (R4) is present in addition to a fourfold axis of inversion (4). The symbol 'n' denotes the presence of a center of symmetry.

The R4×4n structure is characterized by a 4-fold rotation axis that is parallel to one of the crystal's principal axes, and a 4-fold axis of inversion that is also parallel to one of the principal axes. A center of symmetry is located at the intersection of the two axes, creating the R4×4n setting.

In the R4×4n structure, the fourfold rotation axis and the fourfold axis of inversion generate a cube-like symmetry environment, with the fourfold axis of rotation parallel to one of the cube's principal diagonals. When a fourfold axis of rotation is combined with a fourfold axis of inversion, the structure exhibits a higher level of symmetry than is present in the point group with a single fourfold rotation axis.

The R4×4n structure is associated with certain chemical compounds that exhibit integrated structural and spatial symmetry properties. This structure is denoted as a point group and is typically designated as'mm2' or 'D2d' in space group notation.

R4×4n is of interest in mineralogy and materials science due to the integrated symmetry displayed by crystalline materials that exhibit this structure.