Buy article online - an online subscription or single-article purchase is required to access this article.
The structure of KNb5O13 consists of two-dimensional slabs of edge- and corner-sharing NbO6 octahedra, and these slabs are interconnected to form the three-dimensional framework. The K+ cations reside in the empty channels. Among the three crystallographically independent Nb atoms, the coordination around the Nb atom bridging the slabs is more regular than those of the other Nb atoms. A bond-valence calculation indicates that the charge balance should be represented by [K+][Nb5+]5[O2-]13.
Supporting information
Key indicators
- Single-crystal X-ray study
- T = 150 K
- Mean (b-O)= 0.002 Å
- R factor = 0.019
- wR factor = 0.045
- Data-to-parameter ratio = 13.2
checkCIF/PLATON results
No syntax errors found
No errors found in this datablock
Data collection: RAPID-AUTO (Rigaku, 2005); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: locally modified version of ORTEPII (Johnson, 1965); software used to prepare material for publication: WinGX (Farrugia, 1999).
Crystal data top
KNb5O13 | F(000) = 1312 |
Mr = 711.65 | Dx = 4.636 Mg m−3 |
Orthorhombic, Pbcm | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2c 2b | Cell parameters from 9114 reflections |
a = 5.672 (2) Å | θ = 3.1–27.5° |
b = 10.737 (5) Å | µ = 5.93 mm−1 |
c = 16.742 (6) Å | T = 150 K |
V = 1019.7 (7) Å3 | Needle, black |
Z = 4 | 0.20 × 0.04 × 0.04 mm |
Data collection top
Rigaku R-AXIS RAPID diffractometer | 1147 reflections with I > 2σ(I) |
ω scans | Rint = 0.035 |
Absorption correction: numerical (Higashi, 2000) | θmax = 27.5°, θmin = 3.6° |
Tmin = 0.750, Tmax = 0.790 | h = −7→7 |
9248 measured reflections | k = −13→13 |
1205 independent reflections | l = −21→19 |
Refinement top
Refinement on F2 | 0 restraints |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.0113P)2 + 3.9558P] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.019 | (Δ/σ)max < 0.001 |
wR(F2) = 0.046 | Δρmax = 0.59 e Å−3 |
S = 1.19 | Δρmin = −0.73 e Å−3 |
1205 reflections | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
91 parameters | Extinction coefficient: 0.00360 (19) |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
K1 | 0.7871 (2) | 0.32683 (13) | 0.25 | 0.0260 (3) | |
Nb1 | 0.16752 (5) | 0.43808 (2) | 0.076718 (16) | 0.00794 (10) | |
Nb2 | 0.33738 (5) | 0.13515 (3) | 0.136796 (16) | 0.00924 (10) | |
Nb3 | 0.67240 (6) | 0.25 | 0 | 0.00699 (11) | |
O1 | 0.0915 (4) | 0.0171 (2) | 0.13820 (13) | 0.0102 (4) | |
O2 | 0.1265 (4) | 0.2821 (2) | 0.12599 (13) | 0.0098 (4) | |
O3 | 0.1293 (4) | 0.6059 (2) | 0.00428 (12) | 0.0076 (4) | |
O4 | 0.3612 (4) | 0.1239 (2) | 0.01261 (12) | 0.0078 (4) | |
O5 | 0.5920 (4) | 0.0042 (2) | 0.13687 (13) | 0.0105 (4) | |
O6 | 0.5969 (4) | 0.2532 (2) | 0.11116 (12) | 0.0083 (4) | |
O7 | 0.3683 (6) | 0.1567 (3) | 0.25 | 0.0118 (6) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
K1 | 0.0307 (6) | 0.0353 (7) | 0.0120 (5) | −0.0163 (5) | 0 | 0 |
Nb1 | 0.00806 (15) | 0.00846 (16) | 0.00730 (15) | 0.00056 (9) | −0.00037 (10) | −0.00001 (9) |
Nb2 | 0.00973 (15) | 0.00986 (16) | 0.00812 (15) | −0.00192 (10) | 0.00076 (10) | 0.00050 (10) |
Nb3 | 0.00627 (18) | 0.00682 (19) | 0.00789 (19) | 0 | 0 | 0.00135 (13) |
O1 | 0.0095 (10) | 0.0102 (11) | 0.0108 (11) | −0.0022 (8) | −0.0012 (8) | 0.0001 (8) |
O2 | 0.0093 (10) | 0.0088 (10) | 0.0113 (10) | −0.0005 (8) | 0.0021 (8) | 0.0010 (8) |
O3 | 0.0065 (9) | 0.0066 (10) | 0.0096 (9) | −0.0004 (8) | −0.0013 (8) | 0.0002 (8) |
O4 | 0.0081 (9) | 0.0084 (10) | 0.0070 (9) | −0.0007 (8) | −0.0002 (8) | −0.0003 (8) |
O5 | 0.0118 (10) | 0.0095 (11) | 0.0100 (11) | 0.0024 (8) | 0.0006 (8) | −0.0002 (8) |
O6 | 0.0088 (10) | 0.0091 (10) | 0.0070 (10) | −0.0019 (8) | −0.0004 (8) | −0.0015 (8) |
O7 | 0.0121 (15) | 0.0141 (16) | 0.0093 (14) | 0.0002 (13) | 0 | 0 |
Geometric parameters (Å, º) top
K1—O6 | 2.682 (2) | Nb2—O4 | 2.087 (2) |
K1—O6i | 2.682 (2) | Nb2—Nb3 | 3.2214 (8) |
K1—O1ii | 2.855 (3) | Nb3—O6 | 1.910 (2) |
K1—O1iii | 2.855 (3) | Nb3—O6vi | 1.910 (2) |
K1—O2iv | 2.872 (2) | Nb3—O3ix | 1.915 (2) |
K1—O2v | 2.872 (2) | Nb3—O3x | 1.915 (2) |
K1—O7 | 2.996 (4) | Nb3—O4 | 2.234 (2) |
Nb1—O5iii | 1.838 (2) | Nb3—O4vi | 2.234 (2) |
Nb1—O2 | 1.881 (2) | Nb3—Nb2vi | 3.2214 (9) |
Nb1—O4vi | 1.972 (2) | O1—Nb1xi | 1.984 (2) |
Nb1—O1vii | 1.984 (2) | O1—K1ix | 2.855 (3) |
Nb1—O3 | 2.182 (2) | O2—K1xii | 2.872 (2) |
Nb1—O3viii | 2.213 (2) | O3—Nb3x | 1.915 (2) |
Nb2—O1 | 1.885 (2) | O3—Nb1viii | 2.213 (2) |
Nb2—O7 | 1.9175 (9) | O4—Nb1vi | 1.972 (2) |
Nb2—O2 | 1.989 (2) | O5—Nb1ix | 1.838 (2) |
Nb2—O6 | 1.989 (2) | O7—Nb2i | 1.9175 (9) |
Nb2—O5 | 2.015 (2) | | |
| | | |
O6—K1—O6i | 120.16 (10) | O7—Nb2—O2 | 92.82 (12) |
O6—K1—O1ii | 151.19 (8) | O1—Nb2—O6 | 168.16 (9) |
O6i—K1—O1ii | 74.92 (7) | O7—Nb2—O6 | 93.93 (11) |
O6—K1—O1iii | 74.92 (7) | O2—Nb2—O6 | 85.41 (9) |
O6i—K1—O1iii | 151.19 (8) | O1—Nb2—O5 | 93.51 (10) |
O1ii—K1—O1iii | 81.92 (10) | O7—Nb2—O5 | 91.03 (11) |
O6—K1—O2iv | 147.89 (8) | O2—Nb2—O5 | 169.96 (9) |
O6i—K1—O2iv | 66.03 (7) | O6—Nb2—O5 | 85.08 (10) |
O1ii—K1—O2iv | 58.93 (7) | O1—Nb2—O4 | 91.24 (9) |
O1iii—K1—O2iv | 115.58 (8) | O7—Nb2—O4 | 170.31 (11) |
O6—K1—O2v | 66.03 (7) | O2—Nb2—O4 | 89.67 (9) |
O6i—K1—O2v | 147.89 (8) | O6—Nb2—O4 | 76.93 (8) |
O1ii—K1—O2v | 115.58 (8) | O5—Nb2—O4 | 85.06 (9) |
O1iii—K1—O2v | 58.93 (7) | O6—Nb3—O6vi | 154.09 (13) |
O2iv—K1—O2v | 92.61 (10) | O6—Nb3—O3ix | 96.30 (9) |
O6—K1—O7 | 60.09 (5) | O6vi—Nb3—O3ix | 98.84 (9) |
O6i—K1—O7 | 60.09 (5) | O6—Nb3—O3x | 98.84 (9) |
O1ii—K1—O7 | 128.86 (7) | O6vi—Nb3—O3x | 96.30 (9) |
O1iii—K1—O7 | 128.86 (7) | O3ix—Nb3—O3x | 108.05 (13) |
O2iv—K1—O7 | 115.44 (7) | O6—Nb3—O4 | 75.03 (8) |
O2v—K1—O7 | 115.44 (7) | O6vi—Nb3—O4 | 84.50 (8) |
O5iii—Nb1—O2 | 101.27 (10) | O3ix—Nb3—O4 | 88.32 (9) |
O5iii—Nb1—O4vi | 97.61 (10) | O3x—Nb3—O4 | 163.21 (9) |
O2—Nb1—O4vi | 95.80 (9) | O6—Nb3—O4vi | 84.50 (8) |
O5iii—Nb1—O1vii | 95.74 (10) | O6vi—Nb3—O4vi | 75.03 (8) |
O2—Nb1—O1vii | 93.53 (9) | O3ix—Nb3—O4vi | 163.21 (9) |
O4vi—Nb1—O1vii | 161.89 (9) | O3x—Nb3—O4vi | 88.32 (9) |
O5iii—Nb1—O3 | 93.40 (9) | O4—Nb3—O4vi | 75.64 (12) |
O2—Nb1—O3 | 165.05 (9) | Nb1—O2—Nb2 | 132.21 (12) |
O4vi—Nb1—O3 | 84.98 (9) | Nb3x—O3—Nb1 | 129.03 (11) |
O1vii—Nb1—O3 | 82.05 (9) | Nb3x—O3—Nb1viii | 126.61 (11) |
O5iii—Nb1—O3viii | 169.34 (9) | Nb1—O3—Nb1viii | 103.89 (9) |
O2—Nb1—O3viii | 89.13 (9) | Nb1vi—O4—Nb2 | 137.65 (11) |
O4vi—Nb1—O3viii | 83.52 (9) | Nb1vi—O4—Nb3 | 124.97 (10) |
O1vii—Nb1—O3viii | 81.13 (9) | Nb2—O4—Nb3 | 96.34 (8) |
O3—Nb1—O3viii | 76.11 (9) | Nb1ix—O5—Nb2 | 143.21 (12) |
O1—Nb2—O7 | 97.86 (12) | Nb3—O6—Nb2 | 111.39 (10) |
O1—Nb2—O2 | 95.14 (10) | Nb2—O7—Nb2i | 162.6 (2) |
Symmetry codes: (i) x, y, −z+1/2; (ii) −x+1, y+1/2, −z+1/2; (iii) −x+1, y+1/2, z; (iv) x+1, y, −z+1/2; (v) x+1, y, z; (vi) x, −y+1/2, −z; (vii) −x, y+1/2, z; (viii) −x, −y+1, −z; (ix) −x+1, y−1/2, z; (x) −x+1, −y+1, −z; (xi) −x, y−1/2, z; (xii) x−1, y, z. |
Subscribe to Acta Crystallographica Section E: Crystallographic Communications
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.