(Ca(x)Nd(11-x))Ru(4)O(24) (x = 4.175).

Single crystals of the title compound, calcium neodymium ruthenate, (Ca(x)Nd(11-x))Ru(4)O(24) (x = 4.175), have been grown by the flux method. The structure consists of two crystallographically independent RuO(6) octa-hedra, which are isolated from each other and embedded in a matrix composed of the Ca and Nd atoms. There are seven M sites which accommodate the Ca and Nd atoms with different populations. Four M sites at general positions are enriched with Nd, whereas the remaining three M sites on twofold rotation axes are enriched with Ca. The coordination numbers of O atoms to the M sites range from 6 to 9. The mean oxidation state of Ru was estimated at +4.79 from the composition analysis. The title compound is non-centrosymmetric and potentially multiferroic.

Related literature

For related compounds, see: non-centrosymmetric I41 structure of Ca11Re4O24 (Jeitschko et al., 1998 ▶); centrosymmetric I41/a structures of Sr11Re4O24 (Bramnik et al., 2000 ▶) and Ba11Os4O24 (Wakeshima & Hinatsu, 2005 ▶); centrosymmetric I2/a structure of Sr11Os4O24 (Tomaszewska & Müller-Buschbaum, 1993 ▶). For bond-valence sums, see: Adams (2001 ▶); Brown (1992 ▶).

Experimental

Crystal data

Ca4.175Nd6.825Ru4O24

M = 1940.16

Tetragonal,

a = 11.2426 (2) Å

c = 16.1043 (3) Å

V = 2035.52 (6) Å3

Z = 4

Mo Kα radiation

μ = 21.11 mm−1

T = 296 K

0.03 × 0.03 × 0.02 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: numerical (SAINT; Bruker, 2008 ▶) T min = 0.507, T max = 0.863

17423 measured reflections

5779 independent reflections

5453 reflections with I > 2σ(I)

R int = 0.019

Refinement

R[F 2 > 2σ(F 2)] = 0.021

wR(F 2) = 0.047

S = 1.08

5779 reflections

125 parameters

Δρmax = 3.05 e Å−3

Δρmin = −1.86 e Å−3

Absolute structure: Flack (1983 ▶), 2535 Friedel pairs

Flack parameter: 0.44 (2)

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPII (Johnson, 1976 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶) and PLATON (Spek, 2009 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810046593/br2148sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810046593/br2148Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Ca4.175Nd6.825Ru4O24	Dx = 6.331 Mg m−3
Mr = 1940.16	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, I41	Cell parameters from 7875 reflections
Hall symbol: I 4bw	θ = 2.2–40.0°
a = 11.2426 (2) Å	µ = 21.11 mm−1
c = 16.1043 (3) Å	T = 296 K
V = 2035.52 (6) Å3	Block, black
Z = 4	0.03 × 0.03 × 0.02 mm
F(000) = 3444

Bruker APEXII CCD diffractometer	5779 independent reflections
Radiation source: fine-focus sealed tube	5453 reflections with I > 2σ(I)
graphite	Rint = 0.019
φ and ω scans	θmax = 40.0°, θmin = 2.2°
Absorption correction: numerical (SAINT; Bruker, 2008)	h = −19→20
Tmin = 0.507, Tmax = 0.863	k = −20→19
17423 measured reflections	l = −29→27

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	w = 1/[σ2(Fo2) + (0.0127P)2 + 23.2349P] where P = (Fo2 + 2Fc2)/3
R[F2 > 2σ(F2)] = 0.021	(Δ/σ)max = 0.002
wR(F2) = 0.047	Δρmax = 3.05 e Å−3
S = 1.08	Δρmin = −1.85 e Å−3
5779 reflections	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
125 parameters	Extinction coefficient: 0.000440 (12)
0 restraints	Absolute structure: Flack (1983), 2535 Friedel pairs
Primary atom site location: structure-invariant direct methods	Flack parameter: 0.44 (2)

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

	x	y	z	Uiso*/Ueq	Occ. (<1)
Nd1	0.79795 (4)	0.73064 (4)	0.25967 (6)	0.00757 (9)	0.901 (3)
Nd2	0.20206 (4)	0.76978 (4)	−0.00960 (6)	0.00713 (8)	0.878 (3)
Nd3	0.29027 (5)	0.97654 (5)	0.16314 (7)	0.00811 (11)	0.599 (3)
Nd4	0.29060 (5)	0.47661 (5)	0.08656 (7)	0.00821 (11)	0.611 (3)
Nd5	0.0000	0.5000	0.00714 (9)	0.0188 (3)	0.422 (4)
Nd6	0.5000	1.0000	−0.00729 (9)	0.0158 (3)	0.379 (4)
Nd7	0.0000	0.5000	0.21035 (9)	0.0092 (2)	0.047 (3)
Ca1	0.79795 (4)	0.73064 (4)	0.25967 (6)	0.00757 (9)	0.099 (3)
Ca2	0.20206 (4)	0.76978 (4)	−0.00960 (6)	0.00713 (8)	0.122 (3)
Ca3	0.29027 (5)	0.97654 (5)	0.16314 (7)	0.00811 (11)	0.401 (3)
Ca4	0.29060 (5)	0.47661 (5)	0.08656 (7)	0.00821 (11)	0.389 (3)
Ca5	0.0000	0.5000	0.00714 (9)	0.0188 (3)	0.578 (4)
Ca6	0.5000	1.0000	−0.00729 (9)	0.0158 (3)	0.621 (4)
Ca7	0.0000	0.5000	0.21035 (9)	0.0092 (2)	0.953 (3)
Ru1	−0.00013 (6)	0.74968 (6)	0.12491 (7)	0.00535 (4)
Ru2	0.49979 (6)	0.74990 (6)	0.1250	0.00552 (4)
O1	0.1079 (4)	0.6131 (4)	0.0978 (3)	0.0138 (7)*
O2	−0.0089 (4)	0.7999 (4)	0.0077 (3)	0.0065 (7)*
O3	−0.1224 (3)	0.8782 (3)	0.1532 (2)	0.0079 (6)*
O4	−0.1468 (4)	0.6608 (4)	0.1179 (3)	0.0121 (8)*
O5	0.0110 (4)	0.7089 (4)	0.2448 (3)	0.0093 (8)*
O6	0.1409 (4)	0.8488 (4)	0.1334 (3)	0.0106 (7)*
O7	0.3972 (4)	0.6126 (4)	0.1538 (3)	0.0099 (7)*
O8	0.4113 (4)	0.8283 (4)	0.2162 (3)	0.0086 (7)*
O9	0.6105 (3)	0.8799 (3)	0.0988 (3)	0.0066 (6)*
O10	0.3897 (3)	0.8277 (3)	0.0502 (3)	0.0079 (6)*
O11	0.6052 (4)	0.6778 (4)	0.2061 (3)	0.0123 (8)*
O12	0.5873 (4)	0.6714 (4)	0.0346 (4)	0.0094 (7)*

	U11	U22	U33	U12	U13	U23
Nd1	0.00648 (15)	0.00682 (15)	0.00943 (15)	−0.00027 (12)	0.00102 (12)	−0.00061 (12)
Nd2	0.00608 (15)	0.00676 (15)	0.00855 (15)	−0.00038 (12)	0.00078 (12)	−0.00054 (12)
Nd3	0.0085 (2)	0.00601 (19)	0.0098 (2)	−0.00132 (15)	−0.00053 (17)	0.00009 (14)
Nd4	0.00755 (19)	0.00627 (19)	0.0108 (2)	−0.00106 (14)	0.00007 (16)	−0.00121 (14)
Nd5	0.0125 (5)	0.0231 (6)	0.0207 (5)	−0.0049 (4)	0.000	0.000
Nd6	0.0196 (5)	0.0088 (4)	0.0189 (5)	0.0093 (4)	0.000	0.000
Nd7	0.0074 (3)	0.0067 (3)	0.0136 (4)	−0.0004 (3)	0.000	0.000
Ca1	0.00648 (15)	0.00682 (15)	0.00943 (15)	−0.00027 (12)	0.00102 (12)	−0.00061 (12)
Ca2	0.00608 (15)	0.00676 (15)	0.00855 (15)	−0.00038 (12)	0.00078 (12)	−0.00054 (12)
Ca3	0.0085 (2)	0.00601 (19)	0.0098 (2)	−0.00132 (15)	−0.00053 (17)	0.00009 (14)
Ca4	0.00755 (19)	0.00627 (19)	0.0108 (2)	−0.00106 (14)	0.00007 (16)	−0.00121 (14)
Ca5	0.0125 (5)	0.0231 (6)	0.0207 (5)	−0.0049 (4)	0.000	0.000
Ca6	0.0196 (5)	0.0088 (4)	0.0189 (5)	0.0093 (4)	0.000	0.000
Ca7	0.0074 (3)	0.0067 (3)	0.0136 (4)	−0.0004 (3)	0.000	0.000
Ru1	0.00461 (7)	0.00620 (7)	0.00523 (7)	−0.00037 (5)	−0.00005 (5)	0.00051 (5)
Ru2	0.00537 (7)	0.00597 (7)	0.00521 (7)	0.00064 (5)	−0.00009 (5)	0.00053 (5)

Nd1—O11	2.406 (5)	Nd5—O1	2.285 (4)
Nd1—O5i	2.419 (5)	Nd5—O1viii	2.285 (4)
Nd1—O9ii	2.470 (4)	Nd5—O7x	2.389 (4)
Nd1—O4i	2.493 (5)	Nd5—O7iv	2.389 (4)
Nd1—O2iii	2.494 (4)	Nd5—O11iv	2.464 (4)
Nd1—O4iii	2.510 (5)	Nd5—O11x	2.464 (4)
Nd1—O12ii	2.525 (5)	Nd6—O3iv	2.418 (4)
Nd1—O3i	2.548 (4)	Nd6—O3xi	2.418 (4)
Nd1—O3iii	2.764 (4)	Nd6—O10v	2.479 (4)
Nd2—O10	2.408 (4)	Nd6—O10	2.479 (4)
Nd2—O2	2.412 (4)	Nd6—O9v	2.507 (4)
Nd2—O5iv	2.467 (5)	Nd6—O9	2.507 (4)
Nd2—O8iv	2.512 (5)	Nd6—O6iv	2.915 (4)
Nd2—O7iv	2.546 (4)	Nd6—O6xi	2.915 (4)
Nd2—O6	2.562 (5)	Nd7—O2vi	2.377 (4)
Nd2—O6iv	2.589 (4)	Nd7—O2xii	2.377 (4)
Nd2—O1	2.686 (4)	Nd7—O5viii	2.416 (4)
Nd2—O1iv	2.857 (4)	Nd7—O5	2.416 (4)
Nd3—O9v	2.219 (4)	Nd7—O1	2.524 (4)
Nd3—O6	2.262 (4)	Nd7—O1viii	2.524 (4)
Nd3—O8	2.316 (5)	Nd7—O4	2.865 (5)
Nd3—O12vi	2.358 (5)	Nd7—O4viii	2.865 (5)
Nd3—O3vii	2.501 (4)	Ru1—O4	1.931 (5)
Nd3—O10	2.713 (4)	Ru1—O6	1.942 (4)
Nd3—O10vi	2.753 (4)	Ru1—O2	1.973 (4)
Nd3—O5iv	2.864 (4)	Ru1—O5	1.989 (4)
Nd4—O7	2.225 (4)	Ru1—O1	2.005 (4)
Nd4—O4viii	2.292 (5)	Ru1—O3	2.046 (4)
Nd4—O12ix	2.314 (5)	Ru2—O10	1.936 (4)
Nd4—O8iv	2.350 (5)	Ru2—O11	1.942 (5)
Nd4—O1	2.571 (4)	Ru2—O12	1.966 (5)
Nd4—O11iv	2.620 (4)	Ru2—O9	1.965 (4)
Nd4—O11ix	2.845 (4)	Ru2—O7	1.981 (4)
Nd4—O2vi	2.943 (4)	Ru2—O8	1.981 (5)
O4—Ru1—O6	176.1 (2)	O10—Ru2—O11	176.1 (2)
O4—Ru1—O2	92.84 (19)	O10—Ru2—O12	93.5 (2)
O6—Ru1—O2	86.75 (18)	O11—Ru2—O12	90.3 (2)
O4—Ru1—O5	89.49 (19)	O10—Ru2—O9	86.29 (16)
O6—Ru1—O5	90.74 (19)	O11—Ru2—O9	93.92 (18)
O2—Ru1—O5	176.6 (2)	O12—Ru2—O9	81.85 (19)
O4—Ru1—O1	96.22 (18)	O10—Ru2—O7	97.22 (17)
O6—Ru1—O1	87.72 (17)	O11—Ru2—O7	82.67 (18)
O2—Ru1—O1	92.38 (18)	O12—Ru2—O7	96.60 (19)
O5—Ru1—O1	89.79 (18)	O9—Ru2—O7	176.3 (2)
O4—Ru1—O3	78.74 (16)	O10—Ru2—O8	86.56 (19)
O6—Ru1—O3	97.33 (16)	O11—Ru2—O8	89.6 (2)
O2—Ru1—O3	88.71 (16)	O12—Ru2—O8	179.7 (3)
O5—Ru1—O3	89.35 (17)	O9—Ru2—O8	98.42 (18)
O1—Ru1—O3	174.89 (18)	O7—Ru2—O8	83.13 (19)