The compound AlNbO4 has been studied by single crystal X-ray precession photographs and X-ray powder diffraction. Unit cell dimensions were calculated using a least squares analysis that refined to a Δ2θ° of no more than 0.03°. A monoclinic cell was found with space group C2/m, a = 12.1558(5)Å, b = 3.7345(2)Å, c = 6.4886(3)Å, and β = 107.613(4)°.

The complexes [C(NH2)3]3MF6, M = Cr, Fe have been isolated from aqueous solutions of the corresponding fluorides. The compounds are isostructural and crystallize in the cubic space group with a = 14.0667 (6) Å for M = Cr, a = 14.1246(8) Å for M = Fe and Z = 8. The MF63− anions are arranged as Na+ and Cl− in the NaCl lattice. Guanidinium cations are distributed on 24-fold general position.

X-ray powder diffraction data for clemizole hydrochloride (1-p-chlorob-enzyl-2-pyrrolidin-1′-ylmethyl-benziminazole hydrochloride, C19H20ClN3.HCl) and cyclizine hydrochloride (1-benzhydryl-4-methylpiperazine hydrochloride, C18H22N2.HCl) are reported. Crystals of clemizole hydrochloride are monoclinic, space group P21/n with a = 29.940(5) Å, b = 10.963(2)Å, c = 5.515(2)Å, β = 90.98 (3)°, Z = 4 and Dx = 1.330g cm−3. Crystals of cyclizine hydrochloride are orthorhombic, space group Pna21 (or Pnam), with a = 11.816(1)Å, b = 13.609(2)Å, c = 9.999(1 )Å, Z = 4 and Dx = 1.251g cm−3.

Six acentric tartrates and tartrato-antimonates have been investigated by means of X-ray powder diffraction. Single crystals were obtained by evaporation from aqueous solutions. The compounds have attracted attention because of their electrostrictive and electro-optical effects. Complete crystal data for the six compounds are reported. X-ray powder diffraction patterns for Rb2C4H4O6 and Ca [Sb2{C4H2O6}2]·2H2O are given.

An indexed powder diffraction pattern and related crystallographic data are reported for a new phase, BaCu(C2O4)2·6H2O, which was a major product in the coprecipitation of barium and copper oxalates.

Recent developments in the Rietveld method for the analysis of powder diffraction data have seen the method evolve from its original purpose of crystal structure refinement to nclude the determination of phase abundance in polycrysalline mixtures and the estimation of crystal size and strain parameters. However, the Rietveld method is not easy to use and may deter many powder diffractionists, who are not inerested in structure refinement per se, from using the method in its non-structural applications.

In order to overcome the difficulties in using the Rietveld method, a program, QPDA (for Quantitative Powder Diffraction Analysis), has been written that sets the conditions necessary for a single or multi-phase refinement, runs the Rietveld program and extracts phase abundance and size/strain information from the refined parameters. The program comprises a user-friendly, default-driven system of subroutines, written initially in VAX Fortran, and operates from a database of inorganic materials frequently encountered in a wide range of minerals and materials science industries.

Equations (3) and (5) should be corrected to read as follows:

Single crystals of Cs3A[B2(SCN)7] with A = Sr, Ba and B = Ag, Cu have been synthesized from aqueous solutions by the evaporation method. The complex thiocyanates are isostructural and crystallize in the tetragonal system with space group .

Complete crystal data and optical data for the four compounds are reported. An X-ray powder diffraction pattern for Cs3Sr[Cu2(SCN)7] is given.