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Since the discovery of electrochemically active LiFePO4, materials with tunnel and layered structures built up of transition metals and polyanions have become the subject of much research. A new quaternary arsenate, sodium calcium trinickel aluminium triarsenate, NaCa1–xNi3–2xAl2x(AsO4)3 (x = 0.23), was synthesized using the flux method in air at 1023 K and its crystal structure was determined from single-crystal X-ray diffraction (XRD) data. This material was also characterized by qualitative energy-dispersive X-ray spectroscopy (EDS) analysis and IR spectroscopy. The crystal structure belongs to the α-CrPO4 type with the space group Imma. The structure is described as a three-dimensional framework built up of corner-edge-sharing NiO6, (Ni,Al)O6 and AsO4 polyhedra, with channels running along the [100] and [010] directions, in which the sodium and calcium cations are located. The proposed structural model has been validated by bond-valence-sum (BVS) and charge-distribution (CHARDI) tools. The sodium ionic conduction pathways in the anionic framework were investigated by means of the bond-valence site energy (BVSE) model, which predicted that the studied material will probably be a very poor Na+ ion conductor (bond-valence activation energy ∼7 eV).
Supporting information
CCDC reference: 1574601
Data collection: CAD-4 EXPRESS (Duisenberg, 1992; Macícek & Yordanov, 1992); cell refinement: CAD-4 EXPRESS (Duisenberg, 1992; Macícek & Yordanov, 1992); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015); molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: WinGX (Farrugia, 2012) and publCIF (Westrip, 2010).
Sodium calcium trinickel aluminium triarsenate
top
Crystal data top
NaCa0.77Ni2.54Al0.46(AsO4)3 | Dx = 4.477 Mg m−3 |
Mr = 632.15 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, Imma | Cell parameters from 25 reflections |
a = 10.419 (2) Å | θ = 12.2–14.6° |
b = 13.496 (2) Å | µ = 16.15 mm−1 |
c = 6.669 (2) Å | T = 298 K |
V = 937.8 (4) Å3 | Prism, green-yellow |
Z = 4 | 0.23 × 0.10 × 0.09 mm |
F(000) = 1194 | |
Data collection top
Enraf–Nonius CAD-4 diffractometer | Rint = 0.019 |
Radiation source: fine-focus sealed tube | θmax = 26.9°, θmin = 3.0° |
ω/2θ scans | h = −1→13 |
Absorption correction: ψ scan (North et al., 1968) | k = −1→17 |
Tmin = 0.536, Tmax = 0.860 | l = −8→8 |
1285 measured reflections | 2 standard reflections every 120 reflections |
566 independent reflections | intensity decay: 1% |
521 reflections with I > 2σ(I) | |
Refinement top
Refinement on F2 | 1 restraint |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.0313P)2 + 3.2165P] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.020 | (Δ/σ)max = 0.069 |
wR(F2) = 0.058 | Δρmax = 0.86 e Å−3 |
S = 1.13 | Δρmin = −0.93 e Å−3 |
566 reflections | Extinction correction: SHELXL-2016/4 (Sheldrick 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
60 parameters | Extinction coefficient: 0.00072 (13) |
Special details top
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell esds are taken
into account individually in the estimation of esds in distances, angles
and torsion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds involving l.s. planes. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
CA1 | 0.500000 | 0.750000 | 0.9258 (4) | 0.0324 (6) | 0.774 |
NA1 | 0.000000 | 0.500000 | 0.500000 | 0.0324 (9) | |
NI1 | 0.500000 | 0.000000 | 0.500000 | 0.0084 (4) | 0.543 (8) |
AL1 | 0.500000 | 0.000000 | 0.500000 | 0.0084 (4) | 0.457 (8) |
NI2 | 0.750000 | 0.36287 (5) | 0.750000 | 0.0086 (2) | |
AS1 | 0.500000 | 0.250000 | 0.56155 (10) | 0.0062 (2) | |
AS2 | 0.750000 | 0.57131 (4) | 0.750000 | 0.00680 (18) | |
O1 | 0.500000 | 0.1487 (3) | 0.4177 (6) | 0.0184 (8) | |
O2 | 0.6251 (3) | 0.250000 | 0.7227 (5) | 0.0097 (7) | |
O3 | 0.6949 (3) | 0.63540 (18) | 0.9462 (4) | 0.0146 (6) | |
O4 | 0.8679 (2) | 0.48424 (18) | 0.7979 (4) | 0.0103 (5) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
CA1 | 0.0389 (14) | 0.0306 (13) | 0.0277 (12) | 0.000 | 0.000 | 0.000 |
NA1 | 0.0195 (17) | 0.065 (3) | 0.0123 (15) | 0.000 | 0.000 | 0.0010 (17) |
NI1 | 0.0069 (6) | 0.0118 (7) | 0.0063 (6) | 0.000 | 0.000 | −0.0014 (4) |
AL1 | 0.0069 (6) | 0.0118 (7) | 0.0063 (6) | 0.000 | 0.000 | −0.0014 (4) |
NI2 | 0.0077 (3) | 0.0076 (3) | 0.0105 (3) | 0.000 | −0.0005 (2) | 0.000 |
AS1 | 0.0058 (3) | 0.0069 (3) | 0.0060 (3) | 0.000 | 0.000 | 0.000 |
AS2 | 0.0091 (3) | 0.0062 (3) | 0.0051 (3) | 0.000 | 0.00160 (16) | 0.000 |
O1 | 0.0178 (18) | 0.0169 (18) | 0.0204 (19) | 0.000 | 0.000 | −0.0122 (15) |
O2 | 0.0085 (16) | 0.0106 (16) | 0.0101 (15) | 0.000 | −0.0048 (14) | 0.000 |
O3 | 0.0195 (13) | 0.0174 (14) | 0.0069 (11) | 0.0060 (11) | 0.0014 (10) | −0.0035 (10) |
O4 | 0.0108 (12) | 0.0089 (10) | 0.0112 (10) | 0.0014 (10) | 0.0001 (11) | −0.0004 (9) |
Geometric parameters (Å, º) top
CA1—O3 | 2.556 (3) | NI2—O2xvi | 2.012 (2) |
CA1—O3i | 2.556 (3) | NI2—O2 | 2.012 (2) |
CA1—O3ii | 2.556 (3) | NI2—O4xxiii | 2.072 (3) |
CA1—O3iii | 2.556 (3) | NI2—O4 | 2.072 (3) |
CA1—O1iv | 2.668 (5) | NI2—O3xxiv | 2.106 (3) |
CA1—O1v | 2.668 (5) | NI2—O3xxv | 2.106 (3) |
CA1—O2vi | 2.682 (4) | NI2—AS2 | 2.8132 (9) |
CA1—O2vii | 2.682 (4) | NI2—NA1xxvi | 3.6042 (6) |
CA1—AS1v | 3.250 (3) | NI2—NA1ix | 3.6042 (6) |
CA1—NA1viii | 3.4102 (6) | NI2—CA1vii | 3.7123 (16) |
CA1—NA1ix | 3.4102 (6) | NI2—CA1xxii | 3.7123 (16) |
CA1—AS1vii | 3.419 (3) | AS1—O1 | 1.670 (4) |
NA1—O4ii | 2.426 (3) | AS1—O1xxvii | 1.670 (4) |
NA1—O4x | 2.426 (3) | AS1—O2 | 1.689 (3) |
NA1—O4v | 2.426 (3) | AS1—O2xxvii | 1.689 (3) |
NA1—O4xi | 2.426 (3) | AS1—CA1v | 3.250 (3) |
NA1—O3xii | 2.755 (3) | AS1—CA1vii | 3.419 (3) |
NA1—O3xiii | 2.755 (3) | AS2—O3xxiii | 1.670 (3) |
NA1—O3xiv | 2.755 (3) | AS2—O3 | 1.671 (2) |
NA1—O3xv | 2.755 (3) | AS2—O4 | 1.730 (2) |
NA1—AS2xii | 3.2390 (5) | AS2—O4xxiii | 1.730 (2) |
NA1—AS2xiii | 3.2390 (5) | AS2—NA1ix | 3.2390 (5) |
NA1—AS2v | 3.2390 (5) | AS2—NA1xxvi | 3.2390 (5) |
NA1—AS2xi | 3.2390 (5) | O1—CA1v | 2.668 (5) |
NI1—O4xvi | 1.938 (2) | O2—NI2xvi | 2.012 (2) |
NI1—O4xvii | 1.938 (2) | O2—CA1vii | 2.682 (4) |
NI1—O4xviii | 1.938 (2) | O3—NI2xxviii | 2.106 (3) |
NI1—O4xix | 1.938 (2) | O3—NA1ix | 2.755 (3) |
NI1—O1xx | 2.080 (4) | O4—AL1viii | 1.938 (2) |
NI1—O1 | 2.080 (4) | O4—NI1viii | 1.938 (2) |
NI1—NA1xxi | 3.3344 (10) | O4—NA1xxvi | 2.426 (3) |
NI1—NA1xxii | 3.3344 (10) | | |
| | | |
O3—CA1—O3i | 74.47 (12) | O4xvi—NI1—O1xx | 85.55 (10) |
O3—CA1—O3ii | 105.19 (12) | O4xvii—NI1—O1xx | 94.45 (10) |
O3i—CA1—O3ii | 173.88 (16) | O4xviii—NI1—O1xx | 94.45 (10) |
O3—CA1—O3iii | 173.88 (16) | O4xix—NI1—O1xx | 85.55 (10) |
O3i—CA1—O3iii | 105.19 (12) | O4xvi—NI1—O1 | 94.45 (10) |
O3ii—CA1—O3iii | 74.47 (12) | O4xvii—NI1—O1 | 85.55 (10) |
O3—CA1—O1iv | 74.67 (8) | O4xviii—NI1—O1 | 85.55 (10) |
O3i—CA1—O1iv | 110.85 (10) | O4xix—NI1—O1 | 94.45 (10) |
O3ii—CA1—O1iv | 74.67 (8) | O1xx—NI1—O1 | 180.0 |
O3iii—CA1—O1iv | 110.85 (10) | O4xvi—NI1—NA1xxi | 45.94 (7) |
O3—CA1—O1v | 110.86 (10) | O4xvii—NI1—NA1xxi | 134.06 (7) |
O3i—CA1—O1v | 74.67 (8) | O4xviii—NI1—NA1xxi | 134.06 (7) |
O3ii—CA1—O1v | 110.85 (10) | O4xix—NI1—NA1xxi | 45.94 (7) |
O3iii—CA1—O1v | 74.67 (8) | O1xx—NI1—NA1xxi | 74.71 (10) |
O1iv—CA1—O1v | 61.67 (17) | O1—NI1—NA1xxi | 105.29 (10) |
O3—CA1—O2vi | 64.36 (8) | O4xvi—NI1—NA1xxii | 134.06 (7) |
O3i—CA1—O2vi | 64.36 (8) | O4xvii—NI1—NA1xxii | 45.94 (7) |
O3ii—CA1—O2vi | 109.83 (11) | O4xviii—NI1—NA1xxii | 45.94 (7) |
O3iii—CA1—O2vi | 109.83 (11) | O4xix—NI1—NA1xxii | 134.06 (7) |
O1iv—CA1—O2vi | 138.63 (7) | O1xx—NI1—NA1xxii | 105.29 (10) |
O1v—CA1—O2vi | 138.63 (7) | O1—NI1—NA1xxii | 74.71 (10) |
O3—CA1—O2vii | 109.83 (11) | NA1xxi—NI1—NA1xxii | 180.0 |
O3i—CA1—O2vii | 109.83 (11) | O2xvi—NI2—O2 | 81.57 (15) |
O3ii—CA1—O2vii | 64.36 (8) | O2xvi—NI2—O4xxiii | 174.85 (11) |
O3iii—CA1—O2vii | 64.36 (8) | O2—NI2—O4xxiii | 101.60 (10) |
O1iv—CA1—O2vii | 138.63 (7) | O2xvi—NI2—O4 | 101.60 (10) |
O1v—CA1—O2vii | 138.63 (7) | O2—NI2—O4 | 174.85 (11) |
O2vi—CA1—O2vii | 58.14 (15) | O4xxiii—NI2—O4 | 75.53 (13) |
O3—CA1—AS1v | 93.06 (8) | O2xvi—NI2—O3xxiv | 95.61 (12) |
O3i—CA1—AS1v | 93.06 (8) | O2—NI2—O3xxiv | 85.36 (12) |
O3ii—CA1—AS1v | 93.06 (8) | O4xxiii—NI2—O3xxiv | 88.73 (10) |
O3iii—CA1—AS1v | 93.06 (8) | O4—NI2—O3xxiv | 90.27 (10) |
O1iv—CA1—AS1v | 30.84 (8) | O2xvi—NI2—O3xxv | 85.36 (12) |
O1v—CA1—AS1v | 30.84 (8) | O2—NI2—O3xxv | 95.61 (12) |
O2vi—CA1—AS1v | 150.93 (8) | O4xxiii—NI2—O3xxv | 90.27 (10) |
O2vii—CA1—AS1v | 150.93 (8) | O4—NI2—O3xxv | 88.73 (10) |
O3—CA1—NA1viii | 126.22 (6) | O3xxiv—NI2—O3xxv | 178.73 (14) |
O3i—CA1—NA1viii | 52.67 (6) | O2xvi—NI2—AS2 | 139.22 (8) |
O3ii—CA1—NA1viii | 126.22 (6) | O2—NI2—AS2 | 139.21 (7) |
O3iii—CA1—NA1viii | 52.67 (6) | O4xxiii—NI2—AS2 | 37.77 (7) |
O1iv—CA1—NA1viii | 129.18 (11) | O4—NI2—AS2 | 37.77 (7) |
O1v—CA1—NA1viii | 67.51 (8) | O3xxiv—NI2—AS2 | 89.37 (7) |
O2vi—CA1—NA1viii | 82.71 (4) | O3xxv—NI2—AS2 | 89.37 (7) |
O2vii—CA1—NA1viii | 82.71 (4) | O2xvi—NI2—NA1xxvi | 87.89 (8) |
AS1v—CA1—NA1viii | 98.35 (4) | O2—NI2—NA1xxvi | 144.53 (9) |
O3—CA1—NA1ix | 52.67 (6) | O4xxiii—NI2—NA1xxvi | 87.20 (7) |
O3i—CA1—NA1ix | 126.22 (6) | O4—NI2—NA1xxvi | 40.27 (7) |
O3ii—CA1—NA1ix | 52.67 (6) | O3xxiv—NI2—NA1xxvi | 129.53 (7) |
O3iii—CA1—NA1ix | 126.22 (6) | O3xxv—NI2—NA1xxvi | 49.62 (7) |
O1iv—CA1—NA1ix | 67.51 (8) | AS2—NI2—NA1xxvi | 59.103 (10) |
O1v—CA1—NA1ix | 129.18 (11) | O2xvi—NI2—NA1ix | 144.53 (9) |
O2vi—CA1—NA1ix | 82.71 (4) | O2—NI2—NA1ix | 87.89 (8) |
O2vii—CA1—NA1ix | 82.71 (4) | O4xxiii—NI2—NA1ix | 40.27 (7) |
AS1v—CA1—NA1ix | 98.35 (4) | O4—NI2—NA1ix | 87.20 (7) |
NA1viii—CA1—NA1ix | 163.31 (9) | O3xxiv—NI2—NA1ix | 49.62 (7) |
O3—CA1—AS1vii | 86.94 (8) | O3xxv—NI2—NA1ix | 129.53 (7) |
O3i—CA1—AS1vii | 86.94 (8) | AS2—NI2—NA1ix | 59.103 (10) |
O3ii—CA1—AS1vii | 86.94 (8) | NA1xxvi—NI2—NA1ix | 118.21 (2) |
O3iii—CA1—AS1vii | 86.94 (8) | O2xvi—NI2—CA1vii | 95.19 (9) |
O1iv—CA1—AS1vii | 149.16 (8) | O2—NI2—CA1vii | 44.61 (10) |
O1v—CA1—AS1vii | 149.16 (8) | O4xxiii—NI2—CA1vii | 89.90 (7) |
O2vi—CA1—AS1vii | 29.07 (8) | O4—NI2—CA1vii | 130.58 (8) |
O2vii—CA1—AS1vii | 29.07 (8) | O3xxiv—NI2—CA1vii | 41.65 (8) |
AS1v—CA1—AS1vii | 180.0 | O3xxv—NI2—CA1vii | 139.14 (8) |
NA1viii—CA1—AS1vii | 81.65 (4) | AS2—NI2—CA1vii | 114.227 (14) |
NA1ix—CA1—AS1vii | 81.65 (4) | NA1xxvi—NI2—CA1vii | 170.85 (3) |
O4ii—NA1—O4x | 180.0 | NA1ix—NI2—CA1vii | 55.539 (12) |
O4ii—NA1—O4v | 110.86 (12) | O2xvi—NI2—CA1xxii | 44.61 (10) |
O4x—NA1—O4v | 69.14 (12) | O2—NI2—CA1xxii | 95.19 (9) |
O4ii—NA1—O4xi | 69.14 (12) | O4xxiii—NI2—CA1xxii | 130.58 (8) |
O4x—NA1—O4xi | 110.86 (12) | O4—NI2—CA1xxii | 89.90 (7) |
O4v—NA1—O4xi | 180.0 | O3xxiv—NI2—CA1xxii | 139.14 (8) |
O4ii—NA1—O3xii | 62.19 (8) | O3xxv—NI2—CA1xxii | 41.65 (8) |
O4x—NA1—O3xii | 117.81 (8) | AS2—NI2—CA1xxii | 114.227 (14) |
O4v—NA1—O3xii | 68.30 (8) | NA1xxvi—NI2—CA1xxii | 55.539 (12) |
O4xi—NA1—O3xii | 111.70 (8) | NA1ix—NI2—CA1xxii | 170.85 (3) |
O4ii—NA1—O3xiii | 117.81 (8) | CA1vii—NI2—CA1xxii | 131.55 (3) |
O4x—NA1—O3xiii | 62.19 (8) | O1—AS1—O1xxvii | 109.9 (3) |
O4v—NA1—O3xiii | 111.70 (8) | O1—AS1—O2 | 111.42 (10) |
O4xi—NA1—O3xiii | 68.30 (8) | O1xxvii—AS1—O2 | 111.42 (10) |
O3xii—NA1—O3xiii | 180.0 | O1—AS1—O2xxvii | 111.42 (10) |
O4ii—NA1—O3xiv | 68.30 (8) | O1xxvii—AS1—O2xxvii | 111.42 (10) |
O4x—NA1—O3xiv | 111.70 (8) | O2—AS1—O2xxvii | 101.0 (2) |
O4v—NA1—O3xiv | 62.19 (8) | O1—AS1—CA1v | 54.96 (14) |
O4xi—NA1—O3xiv | 117.81 (8) | O1xxvii—AS1—CA1v | 54.96 (14) |
O3xii—NA1—O3xiv | 85.05 (11) | O2—AS1—CA1v | 129.51 (12) |
O3xiii—NA1—O3xiv | 94.95 (11) | O2xxvii—AS1—CA1v | 129.50 (12) |
O4ii—NA1—O3xv | 111.70 (8) | O1—AS1—CA1vii | 125.04 (14) |
O4x—NA1—O3xv | 68.30 (8) | O1xxvii—AS1—CA1vii | 125.04 (14) |
O4v—NA1—O3xv | 117.81 (8) | O2—AS1—CA1vii | 50.49 (12) |
O4xi—NA1—O3xv | 62.19 (8) | O2xxvii—AS1—CA1vii | 50.50 (12) |
O3xii—NA1—O3xv | 94.95 (11) | CA1v—AS1—CA1vii | 180.0 |
O3xiii—NA1—O3xv | 85.05 (11) | O3xxiii—AS2—O3 | 117.63 (18) |
O3xiv—NA1—O3xv | 180.0 | O3xxiii—AS2—O4 | 104.61 (13) |
O4ii—NA1—AS2xii | 31.60 (6) | O3—AS2—O4 | 116.83 (12) |
O4x—NA1—AS2xii | 148.40 (6) | O3xxiii—AS2—O4xxiii | 116.83 (12) |
O4v—NA1—AS2xii | 86.51 (6) | O3—AS2—O4xxiii | 104.61 (13) |
O4xi—NA1—AS2xii | 93.49 (6) | O4—AS2—O4xxiii | 94.40 (17) |
O3xii—NA1—AS2xii | 31.04 (5) | O3xxiii—AS2—NI2 | 121.18 (9) |
O3xiii—NA1—AS2xii | 148.96 (5) | O3—AS2—NI2 | 121.18 (9) |
O3xiv—NA1—AS2xii | 70.82 (6) | O4—AS2—NI2 | 47.20 (8) |
O3xv—NA1—AS2xii | 109.18 (6) | O4xxiii—AS2—NI2 | 47.20 (8) |
O4ii—NA1—AS2xiii | 148.40 (6) | O3xxiii—AS2—NA1ix | 146.47 (9) |
O4x—NA1—AS2xiii | 31.60 (6) | O3—AS2—NA1ix | 58.27 (9) |
O4v—NA1—AS2xiii | 93.49 (6) | O4—AS2—NA1ix | 105.91 (9) |
O4xi—NA1—AS2xiii | 86.51 (6) | O4xxiii—AS2—NA1ix | 47.31 (8) |
O3xii—NA1—AS2xiii | 148.96 (5) | NI2—AS2—NA1ix | 72.713 (9) |
O3xiii—NA1—AS2xiii | 31.04 (5) | O3xxiii—AS2—NA1xxvi | 58.27 (9) |
O3xiv—NA1—AS2xiii | 109.18 (6) | O3—AS2—NA1xxvi | 146.47 (9) |
O3xv—NA1—AS2xiii | 70.82 (6) | O4—AS2—NA1xxvi | 47.31 (8) |
AS2xii—NA1—AS2xiii | 180.0 | O4xxiii—AS2—NA1xxvi | 105.91 (9) |
O4ii—NA1—AS2v | 86.51 (6) | NI2—AS2—NA1xxvi | 72.713 (9) |
O4x—NA1—AS2v | 93.49 (6) | NA1ix—AS2—NA1xxvi | 145.426 (18) |
O4v—NA1—AS2v | 31.60 (6) | AS1—O1—NI1 | 129.7 (2) |
O4xi—NA1—AS2v | 148.40 (6) | AS1—O1—CA1v | 94.21 (17) |
O3xii—NA1—AS2v | 70.82 (6) | NI1—O1—CA1v | 136.13 (17) |
O3xiii—NA1—AS2v | 109.18 (6) | AS1—O2—NI2xvi | 123.83 (10) |
O3xiv—NA1—AS2v | 31.04 (5) | AS1—O2—NI2 | 123.83 (10) |
O3xv—NA1—AS2v | 148.96 (5) | NI2xvi—O2—NI2 | 98.43 (15) |
AS2xii—NA1—AS2v | 72.931 (18) | AS1—O2—CA1vii | 100.44 (15) |
AS2xiii—NA1—AS2v | 107.069 (18) | NI2xvi—O2—CA1vii | 103.60 (11) |
O4ii—NA1—AS2xi | 93.49 (6) | NI2—O2—CA1vii | 103.60 (11) |
O4x—NA1—AS2xi | 86.51 (6) | AS2—O3—NI2xxviii | 131.73 (15) |
O4v—NA1—AS2xi | 148.40 (6) | AS2—O3—CA1 | 123.00 (14) |
O4xi—NA1—AS2xi | 31.60 (6) | NI2xxviii—O3—CA1 | 105.15 (11) |
O3xii—NA1—AS2xi | 109.18 (6) | AS2—O3—NA1ix | 90.68 (10) |
O3xiii—NA1—AS2xi | 70.82 (6) | NI2xxviii—O3—NA1ix | 94.77 (9) |
O3xiv—NA1—AS2xi | 148.96 (5) | CA1—O3—NA1ix | 79.80 (8) |
O3xv—NA1—AS2xi | 31.04 (5) | AS2—O4—AL1viii | 123.93 (14) |
AS2xii—NA1—AS2xi | 107.069 (18) | AS2—O4—NI1viii | 123.93 (14) |
AS2xiii—NA1—AS2xi | 72.931 (18) | AL1viii—O4—NI1viii | 0.0 |
AS2v—NA1—AS2xi | 180.0 | AS2—O4—NI2 | 95.03 (11) |
O4xvi—NI1—O4xvii | 180.0 | AL1viii—O4—NI2 | 127.94 (12) |
O4xvi—NI1—O4xviii | 89.50 (15) | NI1viii—O4—NI2 | 127.94 (12) |
O4xvii—NI1—O4xviii | 90.50 (15) | AS2—O4—NA1xxvi | 101.08 (11) |
O4xvi—NI1—O4xix | 90.50 (15) | AL1viii—O4—NA1xxvi | 99.02 (10) |
O4xvii—NI1—O4xix | 89.50 (15) | NI1viii—O4—NA1xxvi | 99.02 (10) |
O4xviii—NI1—O4xix | 180.00 (10) | NI2—O4—NA1xxvi | 106.23 (10) |
Symmetry codes: (i) x, −y+3/2, z; (ii) −x+1, y, z; (iii) −x+1, −y+3/2, z; (iv) x, y+1/2, −z+1; (v) −x+1, −y+1, −z+1; (vi) x, y+1/2, −z+2; (vii) −x+1, −y+1, −z+2; (viii) x+1/2, y+1/2, z+1/2; (ix) −x+1/2, −y+1, z+1/2; (x) x−1, −y+1, −z+1; (xi) x−1, y, z; (xii) x−1/2, y, −z+3/2; (xiii) −x+1/2, −y+1, z−1/2; (xiv) x−1/2, −y+1, z−1/2; (xv) −x+1/2, y, −z+3/2; (xvi) −x+3/2, −y+1/2, −z+3/2; (xvii) x−1/2, y−1/2, z−1/2; (xviii) −x+3/2, y−1/2, z−1/2; (xix) x−1/2, −y+1/2, −z+3/2; (xx) −x+1, −y, −z+1; (xxi) x+1/2, y−1/2, z+1/2; (xxii) x+1/2, y−1/2, z−1/2; (xxiii) −x+3/2, y, −z+3/2; (xxiv) x, −y+1, −z+2; (xxv) −x+3/2, −y+1, z−1/2; (xxvi) x+1, y, z; (xxvii) −x+1, −y+1/2, z; (xxviii) −x+3/2, −y+1, z+1/2. |
CHARDI and BVS calculations of cation polyhedra in three different structural
models: (a) NaCa0.77Ni2.54Al0.46(AsO4)3 (I); (b) NaCaNi3(AsO4)3
and (c) NaCaNi2.58Al0.42(AsO4)3. (Structure described as built on
cation-centered polyhedra). topCation(i) | CN(i) | | ECoN(i) | | | q(i).sof(i) | | | V(i).sof(i) | | | Q(i) | | | q(i)/Q(i) | |
| | a | b | c | a | b | c | a | b | c | a | b | c | a | b | c |
Ca1 | 8 | 7.85 | 7.86 | 7.86 | 1.54 | 2.00 | 2.00 | 1.54 | 1.53 | 1.53 | 1.58 | 2.00 | 1.99 | 0.97 | 1.00 | 1.00 |
Na1 | 8 | 6.82 | 6.81 | 6.81 | 1.00 | 1.00 | 1.00 | 1.11 | 1.11 | 1.11 | 0.97 | 1.00 | 0.97 | 1.03 | 1.00 | 1.03 |
M1 | 6 | 5.77 | 5.81 | 5.79 | 2.46 | 2.00 | 2.46 | 2.45 | 2.43 | 2.46 | 2.46 | 2.09 | 2.42 | 1.00 | 0.96 | 1.00 |
Ni2 | 6 | 5.92 | 5.93 | 5.93 | 2.00 | 2.00 | 2.00 | 2.02 | 2.02 | 2.02 | 1.93 | 1.92 | 1.90 | 1.03 | 1.04 | 1.05 |
As1 | 4 | 4.00 | 4.00 | 4.00 | 5.00 | 5.00 | 5.00 | 5.09 | 5.02 | 5.07 | 5.21 | 5.16 | 5.08 | 0.96 | 0.97 | 0.98 |
As2 | 4 | 3.96 | 3.95 | 3.96 | 5.00 | 5.00 | 5.00 | 4.93 | 4.92 | 4.93 | 4.95 | 4.96 | 4.87 | 1.01 | 1.01 | 1.03 |
Notes: CN is coordination number; sof(Ca) in (a) = 0.77;
M1 = Ni in (b), Ni0.54Al0.46 in (a) and
Ni0.58Al0.42 in (c); V(M1 = Ni1/Al1) = 2.40/2.51 in
(a) and 2.41/2.52 in (c). |
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