Structure characterization with neutron powder data of LaGaO3 and NdGaO3 based on X-ray single-crystal data: evidence for an inversion center

Author(s):  
W. Marti ◽  
P. Fischer ◽  
J. Schefer ◽  
F. Kubel

AbstractFrom neutron powder diffraction intensities it is often problematic to distinguish between centrosymmetry and non-centrosymmetry. X-ray single crystal diffraction may be more accurate. In this paper we compare refinement results of crystal structures on the basis of neutron powder data of orthorhombic NdGaO

2019 ◽  
Vol 17 (1) ◽  
pp. 1116-1123
Author(s):  
Jin-Hui Zhou ◽  
Mao-Jian Shi ◽  
Lin Ding ◽  
Guo-Qiang ShangGuan ◽  
Jun Xu

AbstractThe crystal structures of the title compound, C27H26ClN3O2, were established by single-crystal X-ray diffraction and synchrotron radiation X-ray powder diffraction. The simulated annealing approach and rigid-body Rietveld refinement were applied to the structure solution from powder data. Direct methods and full-matrix least-squares techniques were used to solve and refine the crystal structure from single-crystal data. The title compound crystallized in space group P $\bar{1}$ with lattice parameters a=17.396(7) Å, b= 10.010(4) Å, c=6.833(3) Å, α=77.345(12) °, β= 93.534(6) °, γ=97.210(9) °, unit-cell volume V= 1151.0(2) Å3, Z=2 from powder data, and in space group P $\bar{1}$with lattice parameters α=82.485(2) °, β= 86.5110(10) °, γ=77.518(2) °, a=6.8159(6) Å, b= 10.0003(9) Å, c=17.4140(15) Å, unit-cell volume V =1148.3(2) Å3, Z=2 from single-crystal data. No detectable impurities were observed.


1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.


Sign in / Sign up

Export Citation Format

Share Document