Synthesis, Structure Determination, and Characterizations of a Polar Salt-Inclusion Scandium Germanate, Rb10Li3Sc4Ge12O36F

Chuan Tang; Mingjun Xia; Rukang Li

doi:10.1021/acs.inorgchem.1c03133

Synthesis, Structure Determination, and Characterizations of a Polar Salt-Inclusion Scandium Germanate, Rb₁₀Li₃Sc₄Ge₁₂O₃₆F

Inorg Chem. 2022 Jan 31;61(4):1973-1981. doi: 10.1021/acs.inorgchem.1c03133. Epub 2022 Jan 14.

Authors

Chuan Tang^{1

2}, Mingjun Xia^{1

2}, Rukang Li^{1

2}

Affiliations

¹ Beijing Center for Crystal Research and Development, Key Laboratory of functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 35029373
DOI: 10.1021/acs.inorgchem.1c03133

Abstract

A noncentrosymmetric salt-inclusion germanate, Rb₁₀Li₃Sc₄Ge₁₂O₃₆F, was grown through spontaneous crystallization from a LiF-RbF flux. It crystallizes in the polar space group P31c with cell parameters of a = 10.7587(3) Å, c = 21.6691(10) Å, and Z = 2. Its structure features a complex 3D framework composed of helical [Ge₄O₁₂] chains from condensed [GeO₄] tetrahedra running along the c axis, which are interconnected by the [ScO₆] octahedra. Voids of the 3D net are filled with Rb⁺ ions, Li⁺ ions, and isolated trigonal-bipyramidal [Rb₃Li₂F] superalkali clusters. The title compound has a large band gap of 5.6 eV, a moderate powder second-harmonic-generation response of 0.9KDP, and an extremely small birefringence of 0.001, as was further unraveled by theoretical calculations.