Redetermination of the distorted perovskite Nd(0.53)Sr(0.47)MnO(3).

Neodymium strontium manganese oxide with ideal composition Nd(0.5)Sr(0.5)MnO(3) was reported to have two different structure models. In one model, the x coordinate of an O atom is at x > 1/2, while in the other model the x-coordinate of this atom is at x < 1/2. Difference-density maps around this O atom obtained from the current redetermination clearly show that the structure with the O atom at x < 1/2 result in a more satisfactory model than that with x > 1/2. The title compound with a refined composition of Nd(0.53 (5))Sr(0.47 (5))MnO(3) is a distorted perovskite-type structure with site symmetries 2mm for the statistically occupied (Nd, Sr) site and for the above-mentioned O atom, .2/m. for the Mn atom and ..2 for a second O-atom site. In contrast to previous studies, the displacement factors for all atoms were refined anisotropically.

Related literature

For details of the synthesis, see: Nakamura et al. (1999 ▶). For previous refinements of compounds with composition Nd0.5Sr0.5MnO3 from powder and single-crystal data, see: Woodward et al. (1998 ▶), Caignaert et al. (1998 ▶) and Kajimoto et al. (1999 ▶), Angappane et al. (2004 ▶), respectively. For general background, see: Becker & Coppens (1975 ▶); Dawson et al. (1967 ▶); Libermann et al. (1971 ▶); Mann (1968 ▶), Tanaka & Marumo (1983 ▶).

Experimental

Crystal data

Nd0.53Sr0.47MnO3

M = 218.81

Orthorhombic,

a = 5.4785 (3) Å

b = 5.4310 (3) Å

c = 7.6006 (5) Å

V = 226.14 (2) Å3

Z = 4

Mo Kα radiation

μ = 28.37 mm−1

T = 241 (1) K

0.07 × 0.05 × 0.04 mm

Data collection

MAC Science M06XHF22 four-circle diffractometer

Absorption correction: numerical (CCDABS; Zhurov & Tanaka, 2003 ▶) T min = 0.358, T max = 0.521

1255 measured reflections

966 independent reflections

679 reflections with F > 3σ(F)

R int = 0.022

Refinement

R[F 2 > 2σ(F 2)] = 0.028

wR(F 2) = 0.066

S = 1.19

927 reflections

65 parameters

14 restraints

Δρmax = 2.17 e Å−3

Δρmin = −3.38 e Å−3

Data collection: MXCSYS (MAC Science, 1995 ▶) and IUANGLE (Tanaka et al., 1994 ▶).; cell refinement: RSLC-3 UNICS system (Sakurai & Kobayashi, 1979 ▶); data reduction: RDEDIT (Tanaka, 2008 ▶); program(s) used to solve structure: QNTAO (Tanaka & Ōnuki, 2002 ▶; Tanaka et al., 2008 ▶); program(s) used to refine structure: QNTAO; molecular graphics: ATOMS for Windows (Dowty, 2000 ▶); software used to prepare material for publication: RDEDIT.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808034168/wm2198sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808034168/wm2198Isup2.hkl

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

Nd0.53Sr0.47MnO3	F(000) = 394.64
Mr = 218.81	Dx = 6.479 Mg m−3
Orthorhombic, Ibmm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -I 2c 2c	Cell parameters from 30 reflections
a = 5.4785 (3) Å	θ = 35.6–37.8°
b = 5.4310 (3) Å	µ = 28.37 mm−1
c = 7.6006 (5) Å	T = 241 K
V = 226.14 (2) Å3	Block, black
Z = 4	0.07 × 0.05 × 0.04 mm

MAC Science M06XHF22 four-circle diffractometer	966 independent reflections
Radiation source: fine-focus rotating anode	679 reflections with F > 3σ(F)
graphite	Rint = 0.022
Detector resolution: 1.25x1.25° pixels mm-1	θmax = 74.7°, θmin = 5.3°
integrated intensities data fom ω/2θ scans	h = −12→14
Absorption correction: numerical (CCDABS; Zhurov & Tanaka, 2003)	k = −12→14
Tmin = 0.358, Tmax = 0.521	l = −18→18
1255 measured reflections

Refinement on F	14 restraints
Least-squares matrix: full	Weighting scheme based on measured s.u.'s
R[F2 > 2σ(F2)] = 0.028	(Δ/σ)max = 0.0002
wR(F2) = 0.066	Δρmax = 2.17 e Å−3
S = 1.19	Δρmin = −3.38 e Å−3
927 reflections	Extinction correction: B–C type 1 Gaussian anisotropic (Becker & Coppens, 1975)
65 parameters	Extinction coefficient: 0.029E04 (1)

Experimental. Multiple diffraction was avoided by ψ-scan. Intensities was measured at equi-temperature region of combinaion of angles ω and χ of four-circle diffractometer

Refinement. B—C anisotropic type1 extinction parameters (× 10 4s) are as follows 4087 (526) 6631 (1159) 3088 (391) -790 (416) -1835 (361) 3716 (625)Dawson et al. (1967) proposed the treatment of temperature factors including anharmonic thermal vibration (AHV) effect for high-symmetry crystals by means of series expansion of an one-particle-potential. Tanaka and Marumo (1983) generalized the treatment and anharmonic third and fourth order parameters were refined in the least-square program. AHV parameters were restricted by the site symmetry of Nd/Sr(2 mm), Mn(.2/m.), O1(2 mm) and O2(..2). The anharmonic potentials (V) are represented by the following equation:VNd,Sr,O1=c111u13+c123u1u22+c133u1u32+q1111u14 +q1122u12u22+q1133u12u32+q2222u24 +q2233u22u32+q3333u34 ···(1)VMn=q1111u14+q1122u12u22+q1133u12u32 +q2222u24+q2233u22u32+q3333u34+q1131u13u3 +q2231u22u1u3+q3331u33u1 ···(2)VO2=c211u12u2+c222u23+c233u32u2+c123u1u2u3 +q1111u14+q1122u12u22+q1133u12u32 +q2222u24+q2233u22u32+q3333u34+q1131u13u3 +q2231u22u1u3+q3331u33u1 ···(3)where (u1,u2,u3) is a displacement vector from equilibrium position of each atom. The displacement vector of Nd, Sr, O1 was defined on the coordinate system with axes parallel to the crystal axes, a, b and c. That of Mn and O2 was defined by equation (4) and (5) in terms of the lattice vectors a, b and c in the present study.u1= -0.18253a, u2= 0.18413b, u3= -0.13157c ···(4)u1= -0.11080a-0.14633b, u2= 0.13157c, u3= -0.14506a + 0.11177b ···(5)Since there is strong correlation between harmonic temperature factors and AHV parameters, the AHV parameters and the harmonic temperature factors were refined alternately. The significant AHV parameters cijk (× 10-19JÅ-3) and qiijk (× 10-19JÅ-3) are as follows:Nd and Sr; c111= -5.9 (49), c122= -3.8 (14),Mn; q2231= -1832 (1560),O1: q2222= -9.5 (39), q2233= 569.9 (2279),O2: c211= 3.7 (33), c233= 0.8 (7), c123= -5.5 (23), q2233= 9.1 (79),

	x	y	z	Uiso*/Ueq	Occ. (<1)
Nd	−0.00656 (9)	0	0.25	0.00637 (4)	0.53 (5)
Sr	−0.00656 (9)	0	0.25	0.00637 (4)	0.47 (5)
Mn	0.5	0	0	0.00305 (7)
O1	0.4499 (8)	0	0.25	0.0112 (6)
O2	0.75	0.25	0.0276 (4)	0.0139 (5)

	U11	U22	U33	U12	U13	U23
Nd	0.00653 (6)	0.00685 (7)	0.00574 (8)	0	0	0
Sr	0.00663 (6)	0.00685 (7)	0.00574 (8)	0	0	0
Mn	0.0035 (1)	0.0030 (1)	0.0027 (1)	0	0	0
O1	0.015 (1)	0.017 (1)	0.0015 (2)	0	0	0
O2	0.0148 (7)	0.0116 (7)	0.015 (1)	−0.0058 (6)	0	0

Mn—O1	1.9199 (6)	Ndii—O2	2.545 (2)
Mn—O2	1.9400 (4)	O1—O2	2.721 (3)
Ndi—Ndii	3.8064 (5)	Ndi—Mn	3.3043 (4)
Ndii—O1ii	2.501 (4)	O1iii—O2ii	2.738 (3)
Ndi—O2	2.545 (2)	O1—O1ii	3.489 (4)
Ndii—O1	2.7332 (5)	O2—O2iii	3.8799 (5)
Ndi—O1	2.978 (4)
Ndii—Ndi—Mn	55.020 (8)	Ndi—O1—Mn	81.8 (1)
Mn—Ndi—O1	35.10 (8)	Ndii—O1—Mn	89.07 (3)
Ndi—Ndii—Mn	54.769 (6)	Mn—O1—O1ii	95.15 (9)
Ndi—Ndii—O2	41.61 (5)	Ndii—O1ii—O1	51.11 (8)
Mn—Ndii—O1ii	89.4 (1)	Ndi—O2—Ndii	96.8 (1)
O1—Ndii—O1ii	83.5 (1)	Ndi—O2—O2iii	144.59 (7)
O1ii—Ndii—O2	121.6 (1)	Ndii—O2—O2iii	47.83 (1)
Ndi—Mn—Ndii	70.212 (7)	Ndii—Ndi—O2	41.61 (5)
Ndii—Mn—O1	55.54 (2)	O1—Ndi—O2	58.4 (1)
Ndi—O1—Ndii	83.48 (9)	Ndi—Ndii—O1ii	134.5 (1)
Ndi—O1—O2	52.83 (8)	Mn—Ndii—O1	35.39 (1)
Ndii—O1—O2	55.64 (6)	Mn—Ndii—O2iii	87.76 (5)
O1ii—O1—O2	89.48 (6)	O1—Ndii—O2iii	114.44 (5)
O1—O1ii—O2iii	97.8 (1)	O2—Ndii—O2iii	91.19 (7)
Ndi—O2—O1	68.77 (9)	Ndi—Mn—O2	50.22 (1)
Ndii—O2—O1	62.42 (8)	Ndi—O1—O1ii	128.89 (6)
Ndii—Ndi—O1	45.51 (8)	Ndii—O1—O1ii	45.41 (5)
Mn—Ndi—O2	35.85 (5)	Mn—O1—O2	45.48 (6)
Ndi—Ndii—O1	51.01 (1)	Ndii—O1ii—O2iii	66.4 (1)
Ndi—Ndii—O2iii	132.79 (5)	Ndi—O2—Mn	93.92 (6)
Mn—Ndii—O2	35.71 (5)	Ndii—O2—Mn	94.32 (6)
O1—Ndii—O2	61.94 (5)	Mn—O2—O2iii	88.84 (2)
O1ii—Ndii—O2iii	60.7 (1)	O1—O2—O2iii	89.42 (6)
Ndi—Mn—O1	63.12 (2)	O1ii—O2iii—O2	81.49 (5)
Ndii—Mn—O2	49.98 (1)	Ndii—O2iii—O1ii	52.84 (6)

Table 1

Selected bond lengths (Å)

Mn—O1	1.9199 (6)
Mn—O2	1.9400 (4)
Ndi—O1i	2.501 (4)
Ndii—O2	2.545 (2)
Ndi—O1	2.7332 (5)
Ndii—O1	2.978 (4)

Symmetry codes: (i) ; (ii) .