Withers, RaymondHoche, ThomasLiu, YunEsmaeilzadeh, SaeidKeding, RalfSales, Brian2015-12-132015-12-130022-4596http://hdl.handle.net/1885/78058High-purity Rb2V3O8 has been grown and temperature-dependent electron and single-crystal X-ray diffraction used to carefully investigate its fresnoite-type reciprocal lattice. In contrast to other recently investigated representatives of the fresnoite family of compounds, Rb2V3O8 is not incommensurately modulated with an incommensurate basal plane primary modulation wave vector given by q∼0.3 〈110〉*. A careful low-temperature electron diffraction study has, however, revealed the existence of weak incommensurate satellite reflections characterized by the primitive primary modulation wave vector q1∼0.16c*. The reciprocal space positioning of these incommensurate satellite reflections, the overall (3+1)-d superspace group symmetry, as well as the shapes of the refined displacement ellipsoids determined from single-crystal XRD refinement, are all consistent with their arising from a distinct type of condensed rigid unit modes (RUMs) of distortion of the Rb2V3O8 parent structure.Keywords: Crystal growth; Crystal lattices; Electron diffraction; Satellites; Single crystals; Thermal effects; Vectors; X ray diffraction analysis; Rigid unit modes (RUM); Single-crystal X-ray diffraction; Rubidium compounds; chemical compound; rubidium; article; Frozen RUM mode; Low-temperature average structure refinement; Low-temperature incommensurate phase transition; Rb2V3O8 fresnoite; Temperature-dependent electron diffraction study200410.1016/j.jssc.2004.05.0562016-02-24