Buy article online - an online subscription or single-article purchase is required to access this article.
O. Yakubovich,
G. Kiriukhina,
L. Shvanskaya,
O. Maximova,
A. Volkov,
O. Dimitrova,
E. Ovchenkov,
O. Yumashev,
A. Iqbal,
B. Rahaman,
T. Saha-Dasgupta and
A. Vasiliev Rubidium tetramanganese tris(phosphate), RbMn4(PO4)3, has been synthesized as single crystals under hydrothermal conditions. The crystal structure was refined in the space group Pnnm (D2h12). It is argued that the size factor RM/RA, i.e. the ratio of the A+ ionic radius to the M2+ ionic radius, within the morphotropic series AM4(TO4)3 corresponds to a specific type of crystal structure. At low temperatures, the antiferromagnet superimposed on a buckled kagomé network in RbMn4(PO4)3 experiences a transition into a long-range ordered state with finite spontaneous magnetization. First principles calculations provide the dominant magnetic exchange interactions both within and between the kagomé layers. The analysis of these interactions allows us to suggest a model of alternating ferromagnetic and antiferromagnetic arrangements within chains of Mn3 atoms.
Supporting information
CCDC reference: 1838351
Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: SHELXL2016 (Sheldrick, 2015b).
Rubidium tetramanganese orthophosphate
top
Crystal data top
RbMn4(PO3)4 | Dx = 3.675 Mg m−3 |
Mr = 590.13 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, Pnnm | Cell parameters from 9905 reflections |
a = 16.746 (8) Å | θ = 3.2–32.5° |
b = 9.877 (3) Å | µ = 9.68 mm−1 |
c = 6.4492 (10) Å | T = 293 K |
V = 1066.6 (6) Å3 | Prism, colorless |
Z = 4 | 0.34 × 0.15 × 0.09 mm |
F(000) = 1112 | |
Data collection top
Agilent Xcalibur Sapphire3 diffractometer | 1679 independent reflections |
Radiation source: Enhance (Mo) X-ray Source | 1653 reflections with I > 2σ(I) |
Detector resolution: 16.0630 pixels mm-1 | Rint = 0.039 |
ω scans | θmax = 30.0°, θmin = 3.2° |
Absorption correction: gaussian (CrysAlis PRO; Agilent, 2012) | h = −23→23 |
Tmin = 0.096, Tmax = 0.522 | k = −13→13 |
19493 measured reflections | l = −9→9 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.024 | w = 1/[σ2(Fo2) + (0.019P)2 + 2.4P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.054 | (Δ/σ)max < 0.001 |
S = 1.16 | Δρmax = 1.31 e Å−3 |
1679 reflections | Δρmin = −1.45 e Å−3 |
110 parameters | Extinction correction: SHELXL2016 (Sheldrick, 2015b), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.0150 (4) |
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 | |
Rb | 0.46839 (2) | 0.29491 (4) | 0.000000 | 0.02093 (11) | |
Mn1 | 0.09562 (3) | 0.54336 (5) | 0.000000 | 0.00788 (11) | |
Mn2 | 0.14050 (3) | 0.97640 (5) | 0.000000 | 0.00848 (11) | |
Mn3 | 0.20370 (2) | 0.24846 (3) | 0.25238 (6) | 0.00975 (10) | |
P1 | 0.28193 (5) | 0.45764 (8) | 0.000000 | 0.00602 (15) | |
P2 | 0.03713 (5) | 0.21432 (8) | 0.000000 | 0.00721 (16) | |
P3 | 0.33131 (5) | 0.04178 (8) | 0.000000 | 0.00614 (15) | |
O1 | 0.24652 (13) | 0.1128 (2) | 0.000000 | 0.0088 (4) | |
O2 | 0.31545 (15) | −0.1136 (2) | 0.000000 | 0.0112 (5) | |
O3 | 0.19573 (13) | 0.3950 (2) | 0.000000 | 0.0086 (4) | |
O4 | 0.27374 (15) | 0.6132 (2) | 0.000000 | 0.0105 (4) | |
O5 | −0.04417 (14) | 0.1482 (3) | 0.000000 | 0.0163 (5) | |
O6 | 0.32168 (10) | 0.40572 (17) | 0.1972 (3) | 0.0123 (3) | |
O7 | 0.37533 (10) | 0.08437 (17) | 0.1943 (3) | 0.0121 (3) | |
O8 | 0.08752 (10) | 0.16968 (19) | 0.1886 (3) | 0.0151 (4) | |
O9 | 0.02312 (14) | 0.3680 (2) | 0.000000 | 0.0150 (5) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Rb | 0.01467 (17) | 0.0315 (2) | 0.01658 (18) | −0.00685 (14) | 0.000 | 0.000 |
Mn1 | 0.0069 (2) | 0.0092 (2) | 0.0075 (2) | 0.00049 (16) | 0.000 | 0.000 |
Mn2 | 0.0073 (2) | 0.0086 (2) | 0.0096 (2) | −0.00197 (16) | 0.000 | 0.000 |
Mn3 | 0.01430 (18) | 0.00802 (16) | 0.00694 (16) | 0.00027 (12) | −0.00095 (12) | 0.00030 (12) |
P1 | 0.0067 (3) | 0.0053 (3) | 0.0061 (3) | −0.0007 (3) | 0.000 | 0.000 |
P2 | 0.0047 (3) | 0.0064 (3) | 0.0105 (4) | −0.0003 (3) | 0.000 | 0.000 |
P3 | 0.0065 (3) | 0.0061 (3) | 0.0058 (3) | 0.0000 (3) | 0.000 | 0.000 |
O1 | 0.0077 (10) | 0.0077 (10) | 0.0110 (10) | 0.0033 (8) | 0.000 | 0.000 |
O2 | 0.0196 (12) | 0.0047 (10) | 0.0093 (11) | −0.0003 (9) | 0.000 | 0.000 |
O3 | 0.0068 (10) | 0.0063 (10) | 0.0127 (11) | −0.0006 (8) | 0.000 | 0.000 |
O4 | 0.0166 (11) | 0.0063 (10) | 0.0085 (10) | −0.0022 (8) | 0.000 | 0.000 |
O5 | 0.0079 (11) | 0.0150 (12) | 0.0261 (14) | −0.0064 (9) | 0.000 | 0.000 |
O6 | 0.0144 (8) | 0.0139 (8) | 0.0087 (7) | 0.0026 (6) | −0.0034 (6) | −0.0002 (6) |
O7 | 0.0139 (8) | 0.0139 (8) | 0.0083 (7) | −0.0038 (6) | −0.0033 (6) | 0.0004 (6) |
O8 | 0.0102 (8) | 0.0206 (9) | 0.0145 (8) | −0.0001 (6) | −0.0024 (6) | 0.0068 (7) |
O9 | 0.0087 (11) | 0.0075 (10) | 0.0288 (14) | 0.0009 (8) | 0.000 | 0.000 |
Geometric parameters (Å, º) top
Rb—O8i | 2.852 (2) | Mn2—O8ix | 2.431 (2) |
Rb—O8ii | 2.852 (2) | Mn2—P2viii | 2.9186 (12) |
Rb—O7iii | 2.8850 (18) | Mn3—O4x | 2.1163 (16) |
Rb—O7 | 2.8850 (18) | Mn3—O2xi | 2.1236 (16) |
Rb—O6iii | 2.975 (2) | Mn3—O8 | 2.1353 (19) |
Rb—O6 | 2.975 (2) | Mn3—O3 | 2.1824 (15) |
Rb—O5i | 3.2800 (7) | Mn3—O1 | 2.2269 (16) |
Rb—O5iv | 3.2800 (7) | Mn3—P1 | 2.9383 (9) |
Rb—P3 | 3.3940 (13) | Mn3—Mn3xii | 3.1938 (9) |
Rb—P2i | 3.4251 (6) | P1—O6iii | 1.5241 (17) |
Rb—P2iv | 3.4251 (6) | P1—O6 | 1.5241 (17) |
Rb—P1 | 3.5117 (16) | P1—O4 | 1.542 (2) |
Mn1—O7v | 2.0704 (17) | P1—O3 | 1.570 (2) |
Mn1—O7vi | 2.0704 (17) | P2—O5 | 1.510 (3) |
Mn1—O9 | 2.115 (3) | P2—O9 | 1.536 (3) |
Mn1—O9vii | 2.172 (3) | P2—O8iii | 1.5445 (18) |
Mn1—O3 | 2.226 (2) | P2—O8 | 1.5445 (18) |
Mn2—O5vii | 2.029 (3) | P3—O7 | 1.5137 (17) |
Mn2—O6vi | 2.1687 (17) | P3—O7iii | 1.5137 (17) |
Mn2—O6v | 2.1687 (17) | P3—O2 | 1.557 (2) |
Mn2—O1viii | 2.229 (2) | P3—O1 | 1.584 (2) |
Mn2—O8viii | 2.431 (2) | | |
| | | |
O8i—Rb—O8ii | 89.52 (8) | P2viii—Mn2—Rbxi | 95.04 (2) |
O8i—Rb—O7iii | 140.54 (5) | Rbvi—Mn2—Rbxi | 103.18 (2) |
O8ii—Rb—O7iii | 99.22 (5) | O4x—Mn3—O2xi | 82.22 (7) |
O8i—Rb—O7 | 99.22 (5) | O4x—Mn3—O8 | 94.47 (8) |
O8ii—Rb—O7 | 140.54 (5) | O2xi—Mn3—O8 | 103.96 (9) |
O7iii—Rb—O7 | 51.50 (7) | O4x—Mn3—O3 | 173.01 (9) |
O8i—Rb—O6iii | 146.46 (5) | O2xi—Mn3—O3 | 97.24 (7) |
O8ii—Rb—O6iii | 103.39 (5) | O8—Mn3—O3 | 92.42 (8) |
O7iii—Rb—O6iii | 68.50 (5) | O4x—Mn3—O1 | 96.55 (7) |
O7—Rb—O6iii | 90.27 (6) | O2xi—Mn3—O1 | 169.86 (9) |
O8i—Rb—O6 | 103.39 (5) | O8—Mn3—O1 | 86.17 (8) |
O8ii—Rb—O6 | 146.46 (5) | O3—Mn3—O1 | 82.74 (7) |
O7iii—Rb—O6 | 90.28 (6) | O4x—Mn3—P1 | 141.49 (7) |
O7—Rb—O6 | 68.49 (5) | O2xi—Mn3—P1 | 91.87 (6) |
O6iii—Rb—O6 | 50.61 (7) | O8—Mn3—P1 | 123.75 (5) |
O8i—Rb—O5i | 48.06 (6) | O3—Mn3—P1 | 31.54 (6) |
O8ii—Rb—O5i | 135.73 (6) | O1—Mn3—P1 | 82.80 (6) |
O7iii—Rb—O5i | 121.07 (6) | O4x—Mn3—Mn3xii | 41.01 (5) |
O7—Rb—O5i | 70.23 (6) | O2xi—Mn3—Mn3xii | 41.24 (5) |
O6iii—Rb—O5i | 107.71 (5) | O8—Mn3—Mn3xii | 101.11 (5) |
O6—Rb—O5i | 57.57 (5) | O3—Mn3—Mn3xii | 138.23 (5) |
O8i—Rb—O5iv | 135.73 (6) | O1—Mn3—Mn3xii | 136.96 (4) |
O8ii—Rb—O5iv | 48.06 (6) | P1—Mn3—Mn3xii | 123.639 (13) |
O7iii—Rb—O5iv | 70.23 (6) | O4x—Mn3—Rbxiii | 79.59 (7) |
O7—Rb—O5iv | 121.07 (6) | O2xi—Mn3—Rbxiii | 69.15 (7) |
O6iii—Rb—O5iv | 57.57 (5) | O8—Mn3—Rbxiii | 36.42 (5) |
O6—Rb—O5iv | 107.71 (5) | O3—Mn3—Rbxiii | 106.78 (6) |
O5i—Rb—O5iv | 158.91 (9) | O1—Mn3—Rbxiii | 120.64 (6) |
O8i—Rb—P3 | 124.29 (4) | P1—Mn3—Rbxiii | 133.52 (2) |
O8ii—Rb—P3 | 124.29 (4) | Mn3xii—Mn3—Rbxiii | 68.057 (11) |
O7iii—Rb—P3 | 26.33 (3) | O6iii—P1—O6 | 113.08 (14) |
O7—Rb—P3 | 26.33 (3) | O6iii—P1—O4 | 111.96 (8) |
O6iii—Rb—P3 | 73.29 (4) | O6—P1—O4 | 111.96 (8) |
O6—Rb—P3 | 73.29 (5) | O6iii—P1—O3 | 105.60 (9) |
O5i—Rb—P3 | 94.75 (5) | O6—P1—O3 | 105.60 (9) |
O5iv—Rb—P3 | 94.75 (5) | O4—P1—O3 | 108.09 (13) |
O8i—Rb—P2i | 26.53 (4) | O6iii—P1—Mn3iii | 59.73 (7) |
O8ii—Rb—P2i | 115.54 (5) | O6—P1—Mn3iii | 114.85 (8) |
O7iii—Rb—P2i | 124.84 (4) | O4—P1—Mn3iii | 131.36 (7) |
O7—Rb—P2i | 75.72 (4) | O3—P1—Mn3iii | 46.64 (6) |
O6iii—Rb—P2i | 133.61 (4) | O6iii—P1—Mn3 | 114.85 (8) |
O6—Rb—P2i | 83.39 (4) | O6—P1—Mn3 | 59.73 (7) |
O5i—Rb—P2i | 25.92 (4) | O4—P1—Mn3 | 131.36 (7) |
O5iv—Rb—P2i | 162.11 (5) | O3—P1—Mn3 | 46.63 (6) |
P3—Rb—P2i | 101.987 (18) | Mn3iii—P1—Mn3 | 67.28 (3) |
O8i—Rb—P2iv | 115.54 (5) | O6iii—P1—Rb | 57.16 (7) |
O8ii—Rb—P2iv | 26.53 (4) | O6—P1—Rb | 57.16 (7) |
O7iii—Rb—P2iv | 75.72 (4) | O4—P1—Rb | 122.33 (10) |
O7—Rb—P2iv | 124.84 (4) | O3—P1—Rb | 129.58 (9) |
O6iii—Rb—P2iv | 83.39 (4) | Mn3iii—P1—Rb | 94.28 (3) |
O6—Rb—P2iv | 133.61 (4) | Mn3—P1—Rb | 94.28 (3) |
O5i—Rb—P2iv | 162.11 (5) | O5—P2—O9 | 106.85 (14) |
O5iv—Rb—P2iv | 25.92 (4) | O5—P2—O8iii | 111.66 (9) |
P3—Rb—P2iv | 101.987 (18) | O9—P2—O8iii | 111.44 (9) |
P2i—Rb—P2iv | 140.59 (3) | O5—P2—O8 | 111.66 (9) |
O8i—Rb—P1 | 124.46 (4) | O9—P2—O8 | 111.44 (9) |
O8ii—Rb—P1 | 124.46 (4) | O8iii—P2—O8 | 103.89 (15) |
O7iii—Rb—P1 | 81.35 (5) | O5—P2—Mn2xiv | 100.73 (11) |
O7—Rb—P1 | 81.35 (5) | O9—P2—Mn2xiv | 152.41 (10) |
O6iii—Rb—P1 | 25.49 (3) | O8iii—P2—Mn2xiv | 56.37 (8) |
O6—Rb—P1 | 25.50 (3) | O8—P2—Mn2xiv | 56.37 (8) |
O5i—Rb—P1 | 82.21 (4) | O5—P2—Rbxv | 71.67 (2) |
O5iv—Rb—P1 | 82.21 (4) | O9—P2—Rbxv | 88.57 (3) |
P3—Rb—P1 | 74.68 (4) | O8iii—P2—Rbxv | 55.58 (7) |
P2i—Rb—P1 | 108.121 (17) | O8—P2—Rbxv | 156.54 (8) |
P2iv—Rb—P1 | 108.121 (17) | Mn2xiv—P2—Rbxv | 100.246 (18) |
O7v—Mn1—O7vi | 144.40 (10) | O5—P2—Rbxiii | 71.67 (2) |
O7v—Mn1—O9 | 107.16 (5) | O9—P2—Rbxiii | 88.57 (3) |
O7vi—Mn1—O9 | 107.16 (5) | O8iii—P2—Rbxiii | 156.54 (8) |
O7v—Mn1—O9vii | 97.83 (5) | O8—P2—Rbxiii | 55.58 (7) |
O7vi—Mn1—O9vii | 97.83 (5) | Mn2xiv—P2—Rbxiii | 100.246 (18) |
O9—Mn1—O9vii | 78.73 (10) | Rbxv—P2—Rbxiii | 140.59 (3) |
O7v—Mn1—O3 | 87.24 (5) | O7—P3—O7iii | 111.79 (14) |
O7vi—Mn1—O3 | 87.24 (5) | O7—P3—O2 | 110.91 (8) |
O9—Mn1—O3 | 83.88 (9) | O7iii—P3—O2 | 110.91 (8) |
O9vii—Mn1—O3 | 162.61 (9) | O7—P3—O1 | 108.28 (9) |
O7v—Mn1—Rbxi | 38.28 (5) | O7iii—P3—O1 | 108.28 (9) |
O7vi—Mn1—Rbxi | 132.35 (5) | O2—P3—O1 | 106.46 (13) |
O9—Mn1—Rbxi | 109.70 (4) | O7—P3—Rb | 57.72 (7) |
O9vii—Mn1—Rbxi | 61.91 (3) | O7iii—P3—Rb | 57.72 (7) |
O3—Mn1—Rbxi | 125.46 (2) | O2—P3—Rb | 147.26 (10) |
O7v—Mn1—Rbvi | 132.35 (5) | O1—P3—Rb | 106.27 (10) |
O7vi—Mn1—Rbvi | 38.28 (5) | P3—O1—Mn3iii | 123.72 (7) |
O9—Mn1—Rbvi | 109.70 (4) | P3—O1—Mn3 | 123.72 (7) |
O9vii—Mn1—Rbvi | 61.91 (3) | Mn3iii—O1—Mn3 | 93.93 (9) |
O3—Mn1—Rbvi | 125.46 (2) | P3—O1—Mn2xiv | 116.53 (13) |
Rbxi—Mn1—Rbvi | 100.00 (2) | Mn3iii—O1—Mn2xiv | 96.16 (7) |
O5vii—Mn2—O6vi | 92.12 (6) | Mn3—O1—Mn2xiv | 96.16 (7) |
O5vii—Mn2—O6v | 92.12 (6) | P3—O2—Mn3xvi | 131.15 (5) |
O6vi—Mn2—O6v | 128.47 (10) | P3—O2—Mn3xvii | 131.15 (5) |
O5vii—Mn2—O1viii | 179.86 (10) | Mn3xvi—O2—Mn3xvii | 97.52 (10) |
O6vi—Mn2—O1viii | 87.82 (5) | P1—O3—Mn3 | 101.83 (9) |
O6v—Mn2—O1viii | 87.82 (5) | P1—O3—Mn3iii | 101.82 (8) |
O5vii—Mn2—O8viii | 100.73 (8) | Mn3—O3—Mn3iii | 96.46 (9) |
O6vi—Mn2—O8viii | 144.08 (7) | P1—O3—Mn1 | 115.66 (12) |
O6v—Mn2—O8viii | 84.77 (6) | Mn3—O3—Mn1 | 118.85 (7) |
O1viii—Mn2—O8viii | 79.40 (7) | Mn3iii—O3—Mn1 | 118.85 (7) |
O5vii—Mn2—O8ix | 100.73 (8) | P1—O4—Mn3v | 127.82 (7) |
O6vi—Mn2—O8ix | 84.77 (6) | P1—O4—Mn3vi | 127.82 (7) |
O6v—Mn2—O8ix | 144.08 (7) | Mn3v—O4—Mn3vi | 97.98 (10) |
O1viii—Mn2—O8ix | 79.40 (7) | P2—O5—Mn2vii | 168.31 (18) |
O8viii—Mn2—O8ix | 60.03 (9) | P2—O5—Rbxiii | 82.42 (4) |
O5vii—Mn2—P2viii | 90.96 (8) | Mn2vii—O5—Rbxiii | 98.91 (4) |
O6vi—Mn2—P2viii | 115.62 (5) | P2—O5—Rbxv | 82.42 (4) |
O6v—Mn2—P2viii | 115.62 (5) | Mn2vii—O5—Rbxv | 98.91 (4) |
O1viii—Mn2—P2viii | 89.19 (7) | Rbxiii—O5—Rbxv | 158.91 (9) |
O8viii—Mn2—P2viii | 31.94 (4) | P1—O6—Mn2x | 140.41 (11) |
O8ix—Mn2—P2viii | 31.94 (4) | P1—O6—Rb | 97.35 (8) |
O5vii—Mn2—Rbvi | 51.945 (14) | Mn2x—O6—Rb | 105.20 (6) |
O6vi—Mn2—Rbvi | 44.23 (5) | P3—O7—Mn1x | 148.04 (11) |
O6v—Mn2—Rbvi | 134.02 (5) | P3—O7—Rb | 95.95 (8) |
O1viii—Mn2—Rbvi | 128.041 (13) | Mn1x—O7—Rb | 115.33 (7) |
O8viii—Mn2—Rbvi | 124.91 (5) | P2—O8—Mn3 | 123.06 (11) |
O8ix—Mn2—Rbvi | 77.78 (5) | P2—O8—Mn2xiv | 91.70 (9) |
P2viii—Mn2—Rbvi | 95.04 (2) | Mn3—O8—Mn2xiv | 92.87 (7) |
O5vii—Mn2—Rbxi | 51.945 (14) | P2—O8—Rbxiii | 97.89 (8) |
O6vi—Mn2—Rbxi | 134.02 (5) | Mn3—O8—Rbxiii | 117.19 (8) |
O6v—Mn2—Rbxi | 44.23 (5) | Mn2xiv—O8—Rbxiii | 134.72 (7) |
O1viii—Mn2—Rbxi | 128.041 (13) | P2—O9—Mn1 | 136.18 (15) |
O8viii—Mn2—Rbxi | 77.78 (5) | P2—O9—Mn1vii | 122.54 (14) |
O8ix—Mn2—Rbxi | 124.91 (5) | Mn1—O9—Mn1vii | 101.27 (10) |
Symmetry codes: (i) x+1/2, −y+1/2, −z+1/2; (ii) x+1/2, −y+1/2, z−1/2; (iii) x, y, −z; (iv) x+1/2, −y+1/2, −z−1/2; (v) −x+1/2, y+1/2, −z+1/2; (vi) −x+1/2, y+1/2, z−1/2; (vii) −x, −y+1, −z; (viii) x, y+1, z; (ix) x, y+1, −z; (x) −x+1/2, y−1/2, z+1/2; (xi) −x+1/2, y+1/2, z+1/2; (xii) x, y, −z+1; (xiii) x−1/2, −y+1/2, −z+1/2; (xiv) x, y−1, z; (xv) x−1/2, −y+1/2, −z−1/2; (xvi) −x+1/2, y−1/2, z−1/2; (xvii) −x+1/2, y−1/2, −z+1/2. |
Bond-valence data for RbMn4(PO4)3 topSymbols ↓×2 and ×2→ indicate a multiplication
of the corresponding contribution in the columns or rows due to symmetry |
Atom | Rb | Mn1 | Mn2 | Mn3 | P1 | P2 | P3 | Σ |
O1 | | | 0.305 | 0.307×2→ | | | 1.087 | 2.01 |
O2 | | | | 0.404×2→ | | | 1.170 | 1.98 |
O3 | | 0.308 | | 0.347×2→ | 1.129 | | | 2.13 |
O4 | | | | 0.414×2→ | 1.218 | | | 2.05 |
O5 | 0.056×2↓ | | 0.524 | | | 1.328 | | 1.96 |
O6 | 0.115×2↓ | | 0.359×2↓ | 0.132 | 1.279×2↓ | | | 1.89 |
O7 | 0.143×2↓ | 0.469×2↓ | | | | | 1.314×2↓ | 1.93 |
O8 | 0.154×2↓ | | 0.177×2↓ | 0.394 | | 1.208×2↓ | | 1.93 |
O9 | | 0.415, 0.356 | | | | 1.238 | | 2.01 |
Σ | 0.94 | 2.02 | 1.90 | 2.00 | 4.91 | 4.98 | 4.89 | |
Crystal data for the morphotropic AM4(TO4)3 series of
compounds (A = Rb, K, NH4 or Na; M = Mn, Fe, Co, Ni or Mg;
T = P or As) topUnit-cell parameters correspond to nonstandard settings of space groups
D2h12 and D2h16. The space groups were
converted in order to make the comparison of the structures easier. |
| Compound | Unit-cell parameters | RM (Å) | RA (Å) | Radius ratio | Reference |
| | a, b, c (Å); V (Å3) | | | RM/RA | |
Space group Pmnn (D2h12) | | | | | | |
1 | RbMn4(AsO4)3* | 6.552, 17.408, 10.109, 1153.0 | 0.80 | 1.47 | 0.54 | MacKay et al. (1996) |
2 | RbMn4(PO4)3** | 6.449, 16.746, 9.877, 1066.7 | | | 0.54 | This work |
3 | NH4Mn4(PO4)3 | 6.464, 16.745, 9.886, 1070.1 | | 1.40 | 0.57 | Neeraj et al. (2002) |
4 | NH4Fe4(PO4)3 | 6.301, 16.622, 9.800, 1026.4 | 0.74 | | 0.53 | Sugiyama et al. (2009) |
5 | KFe4(PO4)3 | 6.273, 16.513, 9.808, 1016.0 | | 1.33 | 0.56 | Matvienko et al. (1981) |
6 | KCo4(PO4)3*** | 6.166,16.482, 9.629, 978.6 | 0.72 | | 0.54 | López et al. (2008) |
7 | RbNi4(PO4)3 | 6.185, 16.346, 9.484, 958.8 | 0.69 | 1.47 | 0.47 | Im et al. (2014) |
8 | KNi4(PO4)3** | 6.155, 16.238, 9.491, 948.6 | | 1.33 | 0.52 | Im et al. (2014) |
9 | KMg4(PO4)3 | 6.171, 16.361, 9.562, 965.4 | 0.66 | | 0.50 | Tomaszewski et al. (2005) |
| | | | | | |
Space group Pmcn (D2h16) | | | | | | |
10 | KMn4(PO4)3 | 6.550, 16.028, 9.977, 1047.4 | 0.80 | 1.33 | 0.60 | Yakubovich et al. (1986) |
11 | NaMg4(PO4)3 | 6.345, 15.240, 9.883, 955.7 | 0.66 | 0.97 | 0.68 | Ben Amara et al. (1983) |
| | | | | | |
Space group Cmcm (D2h17) | | | | | | |
12 | NaNi4(PO4)3 | 6.357, 14.842, 9.892, 933.3 | 0.69 | 0.97 | 0.71 | Anderson et al. (1985) |
| | | | | | |
Space group P1121/n (C2h5) | | | | | | |
13 | NaCo4(PO4)3 | 6.339, 15.301, 9.867, 956.8 ? =91.05° | 0.72 | 0.97 | 0.74 | Baies et al. (2006) |
Notes: (*) T = 150 K; (**) also studied using powder diffraction;
(***) powder data. |
Distribution of cations among the positions in four types of crystal
structures AM4(TO4)3 topSpace group | Compound | Characteristics | Positions of cations | | | | | | | | |
Cmcm | NaNi4(PO4)3 | Cation | Ni1 | Ni2 | | | P1 | P1 | | Na | |
| | Wyckoff site | 8f | 8g | | | 8f | 4c | | 4c | |
| | Site symmetry | m | m | | | m | mm | | mm | |
Pmnn | RbMn4(PO4)3 | Cation | Mn1 | Mn2 | Mn3 | | P1 | P2 | P3 | Rb | |
| | Wyckoff site | 4g | 4g | 8h | | 4g | 4g | 4g | 4g | |
| | Site symmetry | m | m | 1 | | m | m | m | m | |
Pmcn | KMn4(PO4)3 | Cation | Mn1 | Mn2 | Mn3 | | P1 | P2 | P3 | K | |
| | Wyckoff site | 4c | 4c | 8d | | 4c | 4c | 4c | 4c | |
| | Site symmetry | m | m | 1 | | m | m | m | m | |
P1121/n | NaCo4(PO4)3 | Cation | Co1 | Co2 | Co3 | Co4 | P1 | P2 | P3 | Na1 | Na1 |
| | Wyckoff site | 4e | 4e | 4e | 4e | 4e | 4e | 4e | 4e | 4e |
| | Site symmetry | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
Paths and values of magnetic exchange interactions in RbMn4(PO4)3 topInteraction | path | Angle (°) | Distance (Å) | Value (K) |
J1 | Mn3—O—Mn3 | 97.99 & 97.53 | 3.193 | 6.0 |
J2 | Mn3—O—Mn3 | 93.93 & 96.47 | 3.254 | 5.5 |
J3 | Mn1—O—Mn1 | 101.26 | 3.315 | 2.8 |
J4 | Mn2—O—Mn3 | 96.15 | 3.315 | 5.3 |
J5 | Mn1—O—Mn3 | 118.85 | 3.796 | 7.0 |
J6 | Mn2—O—Mn3 | 107.34 | 3.798 | 1.5 |
J7 | Mn3—O—P—O—Mn3, Mn3—O—Mn2—O—Mn3 | | 5.176 | 3.4 |
J8 | Mn1—O—P—O—Mn1, Mn2—O—P—O—Mn2, Mn3-O-Mn3-O-Mn3 | | 6.44 | 0.2 |
Subscribe to Acta Crystallographica Section C: Structural Chemistry
The full text of this article is available to subscribers to the journal.
If you have already registered and are using a computer listed in your registration details, please email
support@iucr.org for assistance.