The structure of Ni(3-amino-4,4′-bipyridine)[Ni(CN)4] (or known as Ni-BpyNH2) in powder form was determined using synchrotron X-ray diffraction and refined using the Rietveld refinement technique (R = 8.8%). The orthorhombic (Cmca) cell parameters were determined to be a = 14.7218(3) Å, b = 22.6615(3) Å, c = 12.3833(3) Å, V = 4131.29(9) Å3, and Z = 8. Ni-BpyNH2 forms a 3-D network, with a 2-D Ni(CN)4 net connecting to each other via the BpyNH2 ligands. There are two independent Ni sites on the net. The 2-D nets are connected to each other via the bonding of the pyridine “N” atom to Ni2. The Ni2 site is of six-fold coordination to N with relatively long Ni2–N distances (average of 2.118 Å) as compared to the four-fold coordinated Ni1–C distances (average of 1.850 Å). The Ni(CN)4 net is arranged in a wave-like fashion. The functional group, –NH2, is disordered and was found to be in the m-position relative to the N atom of the pyridine ring. Instead of having a unique position, N has ¼ site occupancy in each of the four m-positions. The powder reference diffraction pattern for Ni-BpyNH2 was prepared and submitted to the Powder Diffraction File (PDF) at the International Centre of Diffraction Data (ICDD).

The crystal structure of anhydrous Al-MFI (NH4) containing adsorbed Ar has been determined and refined using synchrotron X-ray powder diffraction data taken at 90 K, and optimized using density functional theory techniques. Six highly occupied Ar sites almost completely fill the pore volume of the zeolite. Changing the gas flow from Ar to He at 90 K decreases the Ar occupancies of all six sites, but two decrease more than the others. Warming the sample from 90 to 295 K in Ar flow results in further decreases in site occupancies, but five of the original six sites persist.

We present WALLABY pilot data release 1, the first public release of H i pilot survey data from the Wide-field ASKAP L-band Legacy All-sky Blind Survey (WALLABY) on the Australian Square Kilometre Array Pathfinder. Phase 1 of the WALLABY pilot survey targeted three $60\,\mathrm{deg}^{2}$ regions on the sky in the direction of the Hydra and Norma galaxy clusters and the NGC 4636 galaxy group, covering the redshift range of $z \lesssim 0.08$ . The source catalogue, images and spectra of nearly 600 extragalactic H i detections and kinematic models for 109 spatially resolved galaxies are available. As the pilot survey targeted regions containing nearby group and cluster environments, the median redshift of the sample of $z \approx 0.014$ is relatively low compared to the full WALLABY survey. The median galaxy H i mass is $2.3 \times 10^{9}\,{\rm M}_{{\odot}}$ . The target noise level of $1.6\,\mathrm{mJy}$ per 30′′ beam and $18.5\,\mathrm{kHz}$ channel translates into a $5 \sigma$ H i mass sensitivity for point sources of about $5.2 \times 10^{8} \, (D_{\rm L} / \mathrm{100\,Mpc})^{2} \, {\rm M}_{{\odot}}$ across 50 spectral channels ( ${\approx} 200\,\mathrm{km \, s}^{-1}$ ) and a $5 \sigma$ H i column density sensitivity of about $8.6 \times 10^{19} \, (1 + z)^{4}\,\mathrm{cm}^{-2}$ across 5 channels ( ${\approx} 20\,\mathrm{km \, s}^{-1}$ ) for emission filling the 30′′ beam. As expected for a pilot survey, several technical issues and artefacts are still affecting the data quality. Most notably, there are systematic flux errors of up to several 10% caused by uncertainties about the exact size and shape of each of the primary beams as well as the presence of sidelobes due to the finite deconvolution threshold. In addition, artefacts such as residual continuum emission and bandpass ripples have affected some of the data. The pilot survey has been highly successful in uncovering such technical problems, most of which are expected to be addressed and rectified before the start of the full WALLABY survey.

Background: Spinal cord compression from degenerative cervical myelopathy is characterized by progressive loss of hand dexterity, alongside changes in the metabolite profiles in the brain and spinal cord. Correlating the changing metabolite profile with measures of dexterity following decompression surgery may assist in identifying which patients may benefit most from surgery. Methods: Thirty operative myelopathy patients consented to receive spectroscopy and GRASSP-M dexterity assessments both preoperatively and 6-weeks postoperatively. Magnetic resonance spectroscopy (TE=135) was performed in the motor cortex using a 3 Tesla Siemens MRI scanner at Robarts Research Institute. Spearman correlations were used to evaluate associations between metabolite levels and dexterity (p<0.05 was considered significant). Paired two-tailed Student t-tests were used to assess for postoperative changes in metabolite levels. Results: Postoperatively, we observed a statistically significant (p<0.05) negative correlation (r=-0.44) between the N-acetylaspartate-to-creatine ratio (NAA/Cr) and GRASSP-M dexterity scores. There was no significant difference in NAA, Cr, or NAA/Cr postoperatively. Conclusions: These findings demonstrate that patients with lower postoperative NAA/Cr usually have better recovery of dexterity. This link between the myelopathic metabolite profile and clinically meaningful dexterity values requires further investigation to understand the role of both NAA and Cr in mechanisms of postoperative recovery from myelopathy.

Quaternary selenide, Pb4In2.6Bi3.4Se13 (x = 2.4 member of the Pb4(InxBi6-xSe13 solid solution), was synthesized by a solid-state technique, and its structure was determined using powder X-ray diffraction (XRD). Pb4In2.6Bi3.4Se13 crystallizes in the orthorhombic space group Pbam (No. 55) with Z = 4. Lattice parameters and calculated density were determined to be a = 22.152(5) Å, b = 27.454(5) Å, and c = 4.1354(6) Å, V = 2515.0(11) Å3, and Dx = 7.490 g cm−3. The structure consists of Z-shaped ribbon units and corner-shared infinite one-dimensional [InSe4]∞ chains running parallel to the c-axis. The chains and ribbons are further connected by Pb atoms to form a three-dimensional network. Pb atoms are situated in the center of bicapped trigonal prisms. The compound exhibits a semiconductor feature. The Seebeck coefficient of Pb4In2.6Bi3.4Se13 was found to be −180 μV K−1 at 295 K and −380 μV K−1 at 600 K. Combining the values of Seebeck coefficient, electrical conductivity, and thermal conductivity yield a figure of merit, ZT, of about 0.175 at 700 K. The powder XRD pattern of Pb4In2.6Bi3.4Se13 was also determined.

X-ray reference powder patterns and structures have been determined for a series of cobalt- and tungsten-containing cubic alkaline-earth perovskites, (BaxSr1–x)2CoWO6 (x = 0.1, 0.2, 0.3, 0.5, 0.7, and 0.9). The structure of the end members of the series, Sr2CoWO6 and Ba2CoWO6, were tetragonal and cubic, respectively, agreeing with the literature data. From Rietveld refinements, it was found that when x = 0.1 and 0.2, the structure was tetragonal I4/m (a = 5.60481(6) and 5.62305(11) Å and c = 7.97989(12) and 7.9847(2) Å, respectively; Z = 2). When x > 0.2, the structure was cubic (Fm$\bar{3}$m, No. 225; Z = 4) (from x = 0.3 to 0.9, a increases from 7.98399(13) to 8.08871(10) Å). This tetragonal series of compounds exhibit the characteristics of a distorted double-perovskite structure. The bond valence sum values for the alkaline-earth (Ba, Sr) sites in all (BaxSr1−x)2CoWO6 members are greater than the ideal value of 2.0, indicating over-bonding situation, whereas for the W sites, as x increases, a change from under-bonding to slightly over-bonding situation was observed. Density functional theory calculations revealed that while Sr2CoWO6 is a semiconductor, Ba2CoWO6 and SrBaCoWO6 are half-metals. Powder X-ray diffraction patterns of this series of compounds (BaxSr1−x)2CoWO6, with x = 0.1, 0.2, 0.3, 0.5, 0.7, and 0.9, have been submitted to be included in the Powder Diffraction File.

Structure and optical properties have been successfully determined for a series of niobium- and tantalum-containing layered alkaline-earth silicate compounds, Ba3(Nb6−xTax)Si4O26 (x = 0.6, 1.8, 3.0, 4.2, 5.4). The structure of this solid solution was found to be hexagonal P-62m (No. 189), with Z = 1. With x increases from 0.6 to 5.4, the lattice parameter a increases from 8.98804(8) to 9.00565(9) Å and c decreases from 7.83721(10) to 7.75212(12) Å. As a result, the volume decreases from 548.304(11) to 544.479(14) Å3. The (Nb/Ta)O6 distorted octahedra form continuous chains along the c-axis. These (Nb/Ta)O6 chains are in turn linked with the Si2O7 groups to form distorted pentagonal channels in which Ba ions were found. These Ba2+ ions have full occupancy and a 13-fold coordination environment with neighboring oxygen sites. Another salient feature of the structure is the linear Si–O–Si chains. When x in Ba3(Nb6−xTax)Si4O26 increases, the bond valence sum (BVS) values of the Ba sites increase slightly (2.09–2.20), indicating the size of the cage becoming progressively smaller (over-bonding). While SiO cages are also slightly smaller than ideal (BVS range from 4.16 to 4.19), the (Nb/Ta)O6 octahedral cages are slightly larger than ideal (BVS range from 4.87 to 4.90), giving rise to an under-bonding situation. The bandgaps of the solid solution members were measured between 3.39 and 3.59 eV, and the x = 3.0 member was modeled by density functional theory techniques to be 3.07 eV. The bandgaps of these materials indicate that they are potential candidates for ultraviolet photocatalyst.

Powder X-ray diffraction patterns for three forms of MIL-53(Al), a metal organic framework (MOF) compound with breathing characteristics, were investigated using the Rietveld refinement method. These three samples are referred to as the MIL-53(Al)as-syn (the as synthesized sample), orthorhombic, Pnma, a = 17.064(2) Å, b = 6.6069(9) Å, c = 12.1636(13) Å, V = 1371.3(2) Å3, Z = 4), MIL-53(Al)LT-H (low-temperature hydrated phase, monoclinic P21/c, a = 19.4993(8) Å, b = 15.2347(6) Å, c = 6.5687(3) Å, β = 104.219(4) °, V = 1891.55(10) Å3, Z = 8), and MIL-53(Al)HT-D (high-temperature dehydrated phase, Imma, a = 6.6324(5) Å, b = 16.736(2) Å, c = 12.840(2), V = 1425.2(2) Å3, Z = 4). The crystal structures of the “as-syn” sample and the HT-D sample are confirmed to be the commonly adopted ones. However, the structure of the MIL-53(Al)LT-H phase is confirmed to be monoclinic with a space group of P21/c instead of the commonly accepted space group Cc, resulting in a cell volume double in size. The structure has two slightly different types of channel. The pore volumes and pore surface area were estimated to be 0.11766 (8) cm3/g and 1461.3(10) m2/g for MIL-53(Al)HT-D (high-temperature dehydrated phase), and 0.08628 (5) cm3/g and 1401.6 (10) m2/g for MIL-53(Al)as-syn phases, respectively. The powder patterns for the MIL-53(Al)as-syn and MIL-53(Al)HT-D phases are reported in this paper.

Structural characterization and X-ray reference powder pattern determination have been conducted for the Co- and Zn-containing tridymite derivatives Ba(Co1−xZnx)SiO4 (x = 0.2, 0.4, 0.6, 0.8). The bright blue series of Ba(Co1−xZnx)SiO4 crystallized in the hexagonal P63 space group (No. 173), with Z = 6. While the lattice parameter “a” decreases from 9.126 (2) Å to 9.10374(6) Å from x = 0.2 to 0.8, the lattice parameter “c” increases from 8.69477(12) Å to 8.72200(10) Å, respectively. Apparently, despite the similarity of ionic sizes of Zn2+ and Co2+, these opposing trends are due to the framework tetrahedral tilting of (ZnCo)O4. The lattice volume, V, remains comparable between 626.27 Å3 and 626.017 (7) Å3 from x = 0 to x = 0.8. UV-visible absorption spectrum measurements indicate the band gap of these two materials to be ≈3.3 and ≈3.5 eV, respectively, therefore potential UV photocatalytic materials. Reference powder X-ray diffraction patterns of these compounds have been submitted to be included in the Powder Diffraction File (PDF).

A series of double-perovskite oxides, Sr2RNbO6 (R = Sm, Gd, Dy, Ho, Y, Tm, and Lu) were prepared and their crystal structure and powder diffraction reference patterns were determined using the Rietveld analysis technique. The crystal structure of each of the Sr2RNbO6 phase is reported in this paper. The R = Gd, Ho, and Lu samples were studied using synchrotron radiation, while R = Sm, Dy, Y, and Tm samples were studied using laboratory X-ray diffraction. Members of Sr2RNbO6 are monoclinic with a space group of P21/n and are isostructural with each other. Following the trend of “lanthanide contraction”, from R = Sm to Lu, the lattice parameters “a” of these compounds decreases from 5.84672(10) to 5.78100(3) Å, b from 5.93192(13) to 5.80977(3) Å, c from 8.3142(2) to 8.18957(5) Å, and V decreases from 288.355(11) to 275.057(2) Å3. In this double-perovskite series, the R3+ and Nb5+ ions are structurally ordered. The average Nb–O bond length is nearly constant, while the average R–O bond length decreases with the decreasing ionic radius of R3+. Powder diffraction patterns for these compounds have been submitted to the Powder Diffraction File (PDF).

The crystal structure and powder patterns were prepared for the distorted perovskite series R(Co3/4Ti1/4)O3 (R = La, Pr, Nd, Sm, Eu, Gd, Dy, Ho). The R(Co3/4Ti1/4)O3 members are isostructural with each other and are crystallized in the orthorhombic crystal system with space group Pnma, Z = 4. From R = La to Ho, the lattice parameters a range from 5.4614(3) to 5.5368(2) Å, b range from 7.7442(4) to 7.4859(2) Å, and c range from 5.5046(3) to 5.2170(2) Å. The unit-cell volumes, V which range from 232.81(2) to 216.237(11) Å3 follow the trend of “lanthanide contraction”. The structure distortion of these compounds is evidenced in the tilt angles θ, ϕ, and ω, which represent rotations of an octahedron about the pseudo-cubic perovskite [110]p, [001]p and [111]p axes. All three tilt angles increase across the lanthanide series (for R = La to R = Ho: θ increases from 8.34° to 17.00°, ϕ from 6.24° to 8.53°, and ω from 10.41° to 18.96°), indicating a greater octahedral distortion as the ionic radius of R3+ [r(R3+)] decreases. The bond valence sum values for the (Co/Ti) site and the R site of R(Co3/4Ti1/4)O3 reveal no significant bond strain in these compounds. X-ray diffraction patterns of the R(Co3/4Ti1/4)O3 samples were submitted to the Powder Diffraction File.