Ab initio structure determination of novel borate NaSrBO3

A novel orthoborate, NaSrBO3, has been Successfully synthesized by standard solid-state reaction, and the crystal structure has been determined from powder X-ray diffraction data. It crystallizes in the monoclinic space group P2(1)/c with lattice parameters: a = 5.32446(7) angstrom, b = 9.2684(l) angstrom, 6.06683(8) angstrom, beta = 100.589(l)degrees. The fundamental building units are isolated BO3 groups, which are parallelly distributed along two different directions. Because of the anisotropic polarizations of planar BO3 groups, a considerable birefringence can be expected in it. The Na atoms are six-coordinated with O atoms to form octahedra, and the Sr atoms are nine-coordinated, forming tri-capped trigonal prisms. Those polyhedra connect with each other by bridging-oxygen atoms, forming infinite three-dimensional network, which indicates that the cleaving problem is expected to be overcome during the Course of single-crystal growth. The infrared spectrum has been measured, and the result is consistent with the crystallographic study. Moreover, a comparison of the new structure type with the other known orthoborates is presented here. (c) 2006 Elsevier Inc. All rights reserved.