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Acta Crystallogr Sect E Struct Rep Online. 2008 November 1; 64(Pt 11): i77.

Published online 2008 October 22. doi: 10.1107/S1600536808034168

PMCID: PMC2959730

Correspondence e-mail: pj.ca.hcetin.nts@02051541

Received 2008 September 18; Accepted 2008 October 20.

Copyright © Makita et al. 2008

This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

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 2*mm* 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.

For details of the synthesis, see: Nakamura *et al.* (1999 ). For previous refinements of compounds with composition Nd_{0.5}Sr_{0.5}MnO_{3} 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 ).

- Nd
_{0.53}Sr_{0.47}MnO_{3} *M*= 218.81_{r}- Orthorhombic,
*a*= 5.4785 (3) Å*b*= 5.4310 (3) Å*c*= 7.6006 (5) Å*V*= 226.14 (2) Å^{3}*Z*= 4- Mo
*K*α radiation - μ = 28.37 mm
^{−1} *T*= 241 (1) K- 0.07 × 0.05 × 0.04 mm

*R*[*F*^{2}> 2σ(*F*^{2})] = 0.028*wR*(*F*^{2}) = 0.066*S*= 1.19- 927 reflections
- 65 parameters
- 14 restraints
- Δρ
_{max}= 2.17 e Å^{−3} - Δρ
_{min}= −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

Click here to view.^{(16K, cif)}

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

Click here to view.^{(36K, hkl)}

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

Woodward *et al.* (1998) and Caignaert *et al.* (1998)
determined the structure of Nd_{0.5}Sr_{0.5}MnO_{3} on the basis of powder
X-ray diffraction data, whereas Kajimoto (1999) and Angappane *et
al.*
(2004) used single-crystal X-ray diffraction data for structure
refinements.
Except the model reported by Woodward *et al.* (1998), for all
other
structure models of Nd_{0.5}Sr_{0.5}MnO_{3} the *x*-coordinate of oxygen
atom O1 was reported to be > 1/2. Since a new examination of the
*x*-coordinate of O1 seemed desirable and anisotropic displacement factors
were not reported in the previous studies, we decided to redetermine the
structure of Nd_{0.45}Sr_{0.55}MnO_{3}. The result of the structure analysis
is presented in this communication.

The structure of the title compound derives from the perovskite-type (Fig. 1)
and exhibits an orthorhombic distortion. The site symmetries are 2*mm* for
the statistically occupied [(Nd,Sr)O_{12}] polyhedron and for O1,
.2/*m*. for the distorted [MnO_{6}] octahedron and ..2 for O2.

A large single crystal was grown using a floating zone method (Nakamura
*et al.*, 1999). The bulk sample was put on a piece of filter paper
and was etched by diluted nitric acid under a microscope. Finally, the sample
was shaped into a 0.040 mm × 0.053 mm × 0.065 mm block.
Nd_{0.45}Sr_{0.55}MnO_{3} exhibits a first order phase transition at
T_{N} = 225K. The present diffraction study was carried out at 241 (1) K
close to the phase transition temperature.

The structure of Nd_{1 -}* _{x}*Sr

When the coordinates by Caignaert *et al.* (1998) were used as
starting
parameters for refinement, the *x*-coordinate of O1 converged to 0.518 (1)
with a *R*-factor of 0.0381. Fig. 2 (*a*) shows the difference
density
map onto (010) after this refinement in the range 0< *z* < 1/2 and 0 <
*x* < 1 with the vertical and horizontal lengths of 3.80 Å × 5.48 Å. The cores of Nd/Sr, Mn and O1 are at (0, 1/4), (1/2, 1/2) and (0.52, 1/4).
Since there are two high peaks at *x* = 0.45 and 0.55 in Fig 2
(*a*),
O1 was split into O1(1) at *x*=0.45 and O1(2) at *x*=0.55. The site
occupation factors of O1(1) and O1(2) became 0.96 (6) and 0.04 (6) after the
refinement. Hence O1 was concluded to be located only at *x*=0.45. After
the subsequent refinement the *R*-factor converged at 0.0289 and the
difference density map became likewise more satisfactory (Fig. 2(*b*)).

Although the temperature factor U^{33} of O1 is 0.001 (1) Å^{2} and
almost insignificant, it becomes 0.0015 (2) Å^{2} after the refinement of
anharmonic vibration parameters (Dawson *et al.*, 1967; Tanaka &
Marumo,
1983) as well as the harmonic ones. Finally, refinement of the site
occupation
factors revealed a hole-concentration *x* of 0.47 (5) thus leading to a
composition of Nd_{0.53}Sr_{0.47}MnO_{3}.

The structure of the distorted perovskite Nd0.53Sr0.47MnO3 with displacement ellipsoids drawn at the 90% probability level.

Nd_{0.53}Sr_{0.47}MnO_{3} | F(000) = 394.64 |

M = 218.81_{r} | D_{x} = 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) Å^{3} | 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 | R_{int} = 0.022 |

Detector resolution: 1.25x1.25° pixels mm^{-1} | θ_{max} = 74.7°, θ_{min} = 5.3° |

integrated intensities data fom ω/2θ scans | h = −12→14 |

Absorption correction: numerical (CCDABS; Zhurov & Tanaka, 2003) | k = −12→14 |

T_{min} = 0.358, T_{max} = 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[F^{2} > 2σ(F^{2})] = 0.028 | (Δ/σ)_{max} = 0.0002 |

wR(F^{2}) = 0.066 | Δρ_{max} = 2.17 e Å^{−}^{3} |

S = 1.19 | Δρ_{min} = −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 ^{4}s) 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:V_{Nd,Sr,O1}=c_{111}u_{1}^{3}+c_{123}u_{1}u_{2}^{2}+c_{133}u_{1}u_{3}^{2}+q_{1111}u_{1}^{4}
+q_{1122}u_{1}^{2}u_{2}^{2}+q_{1133}u_{1}^{2}u_{3}^{2}+q_{2222}u_{2}^{4}
+q_{2233}u_{2}^{2}u_{3}^{2}+q_{3333}u_{3}^{4} ···(1)V_{Mn}=q_{1111}u_{1}^{4}+q_{1122}u_{1}^{2}u_{2}^{2}+q_{1133}u_{1}^{2}u_{3}^{2}
+q_{2222}u_{2}^{4}+q_{2233}u_{2}^{2}u_{3}^{2}+q_{3333}u_{3}^{4}+q_{1131}u_{1}^{3}u_{3}
+q_{2231}u_{2}^{2}u_{1}u_{3}+q_{3331}u_{3}^{3}u_{1} ···(2)V_{O2}=c_{211}u_{1}^{2}u_{2}+c_{222}u_{2}^{3}+c_{233}u_{3}^{2}u_{2}+c_{123}u_{1}u_{2}u_{3}
+q_{1111}u_{1}^{4}+q_{1122}u_{1}^{2}u_{2}^{2}+q_{1133}u_{1}^{2}u_{3}^{2}
+q_{2222}u_{2}^{4}+q_{2233}u_{2}^{2}u_{3}^{2}+q_{3333}u_{3}^{4}+q_{1131}u_{1}^{3}u_{3}
+q_{2231}u_{2}^{2}u_{1}u_{3}+q_{3331}u_{3}^{3}u_{1} ···(3)where (u_{1},u_{2},u_{3}) 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.u_{1}= -0.18253a, u_{2}= 0.18413b, u_{3}= -0.13157c ···(4)u_{1}= -0.11080a-0.14633b, u_{2}= 0.13157c, u_{3}=
-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 c_{ijk} (×
10^{-19}JÅ^{-3}) and q_{iijk} (× 10^{-19}JÅ^{-3}) are as follows:Nd and Sr; c_{111}= -5.9 (49), c_{122}= -3.8 (14),Mn; q_{2231}= -1832 (1560),O1: q_{2222}= -9.5 (39), q_{2233}= 569.9 (2279),O2: c_{211}= 3.7 (33), c_{233}= 0.8 (7), c_{123}= -5.5 (23), q_{2233}= 9.1 (79), |

x | y | z | U_{iso}*/U_{eq} | 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) |

U^{11} | U^{22} | U^{33} | U^{12} | U^{13} | U^{23} | |

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) | Nd^{ii}—O2 | 2.545 (2) |

Mn—O2 | 1.9400 (4) | O1—O2 | 2.721 (3) |

Nd^{i}—Nd^{ii} | 3.8064 (5) | Nd^{i}—Mn | 3.3043 (4) |

Nd^{ii}—O1^{ii} | 2.501 (4) | O1^{iii}—O2^{ii} | 2.738 (3) |

Nd^{i}—O2 | 2.545 (2) | O1—O1^{ii} | 3.489 (4) |

Nd^{ii}—O1 | 2.7332 (5) | O2—O2^{iii} | 3.8799 (5) |

Nd^{i}—O1 | 2.978 (4) | ||

Nd^{ii}—Nd^{i}—Mn | 55.020 (8) | Nd^{i}—O1—Mn | 81.8 (1) |

Mn—Nd^{i}—O1 | 35.10 (8) | Nd^{ii}—O1—Mn | 89.07 (3) |

Nd^{i}—Nd^{ii}—Mn | 54.769 (6) | Mn—O1—O1^{ii} | 95.15 (9) |

Nd^{i}—Nd^{ii}—O2 | 41.61 (5) | Nd^{ii}—O1^{ii}—O1 | 51.11 (8) |

Mn—Nd^{ii}—O1^{ii} | 89.4 (1) | Nd^{i}—O2—Nd^{ii} | 96.8 (1) |

O1—Nd^{ii}—O1^{ii} | 83.5 (1) | Nd^{i}—O2—O2^{iii} | 144.59 (7) |

O1^{ii}—Nd^{ii}—O2 | 121.6 (1) | Nd^{ii}—O2—O2^{iii} | 47.83 (1) |

Nd^{i}—Mn—Nd^{ii} | 70.212 (7) | Nd^{ii}—Nd^{i}—O2 | 41.61 (5) |

Nd^{ii}—Mn—O1 | 55.54 (2) | O1—Nd^{i}—O2 | 58.4 (1) |

Nd^{i}—O1—Nd^{ii} | 83.48 (9) | Nd^{i}—Nd^{ii}—O1^{ii} | 134.5 (1) |

Nd^{i}—O1—O2 | 52.83 (8) | Mn—Nd^{ii}—O1 | 35.39 (1) |

Nd^{ii}—O1—O2 | 55.64 (6) | Mn—Nd^{ii}—O2^{iii} | 87.76 (5) |

O1^{ii}—O1—O2 | 89.48 (6) | O1—Nd^{ii}—O2^{iii} | 114.44 (5) |

O1—O1^{ii}—O2^{iii} | 97.8 (1) | O2—Nd^{ii}—O2^{iii} | 91.19 (7) |

Nd^{i}—O2—O1 | 68.77 (9) | Nd^{i}—Mn—O2 | 50.22 (1) |

Nd^{ii}—O2—O1 | 62.42 (8) | Nd^{i}—O1—O1^{ii} | 128.89 (6) |

Nd^{ii}—Nd^{i}—O1 | 45.51 (8) | Nd^{ii}—O1—O1^{ii} | 45.41 (5) |

Mn—Nd^{i}—O2 | 35.85 (5) | Mn—O1—O2 | 45.48 (6) |

Nd^{i}—Nd^{ii}—O1 | 51.01 (1) | Nd^{ii}—O1^{ii}—O2^{iii} | 66.4 (1) |

Nd^{i}—Nd^{ii}—O2^{iii} | 132.79 (5) | Nd^{i}—O2—Mn | 93.92 (6) |

Mn—Nd^{ii}—O2 | 35.71 (5) | Nd^{ii}—O2—Mn | 94.32 (6) |

O1—Nd^{ii}—O2 | 61.94 (5) | Mn—O2—O2^{iii} | 88.84 (2) |

O1^{ii}—Nd^{ii}—O2^{iii} | 60.7 (1) | O1—O2—O2^{iii} | 89.42 (6) |

Nd^{i}—Mn—O1 | 63.12 (2) | O1^{ii}—O2^{iii}—O2 | 81.49 (5) |

Nd^{ii}—Mn—O2 | 49.98 (1) | Nd^{ii}—O2^{iii}—O1^{ii} | 52.84 (6) |

Symmetry codes: (i) *x*+1, *y*, *z*; (ii) −*x*+1/2, *y*+1/2, *z*; (iii) *x*−1/2, *y*+1/2, −*z*.

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: WM2198).

- Angappane, S., Pattabiraman, M., Rangarajan, G., Sethupathi, K. & Sastry, V. S. (2004).
*Phys. Rev.***B69**, 094437-0–094437-8. - Becker, P. J. & Coppens, P. (1975).
*Acta Cryst.*A**31**, 417–425. - Caignaert, V., Millange, F., Hervieu, M., Suard, E. & Raveau, B. (1998).
*Solid State Commun.***99**, 173–177. - Dawson, B., Hurley, A. C. & Maslen, V. W. (1967).
*Proc. R. Soc. London Ser. A*,**298**, 289–306. - Dowty, E. (2000).
*ATOMS for Windows*Shape Software, Kingsport, Tennessee, USA. - Kajimoto, R., Yoshizawa, H., Kawano, H., Kuwahara, H., Tokura, Y., Ohoyama, K. & Ohashi, M. (1999).
*Phys. Rev. B*,**60**, 9506–9517. - Libermann, D. A., Cromer, D. T. & Waber, J. T. (1971).
*C. Phys. Commun.***2**, 107–113. - MAC Science (1995).
*MXCSYS*Bruker AXS Inc., Tsukuba, Ibaraki, Japan. - Mann, J. B. (1968). Los Alamos Scientific Report LA3691, Los Alamos, USA.
- Nakamura, K., Arima, T., Nakazawa, A., Wakabayashi, Y. & Murakami, Y. (1999).
*Phys. Rev.***B60**, 2425–2428. - Sakurai, T. & Kobayashi, K. (1979).
*Rikagaku Kenkyusho Hokoku*,**55**, 69–77. - Tanaka, K. (2008).
*RDEDIT*Unpublished. - Tanaka, K., Kumazawa, S., Tsubokawa, M., Maruno, S. & Shirotani, I. (1994).
*Acta Cryst.*A**50**, 246–252. - Tanaka, K., Makita, R., Funahashi, S., Komori, T. & Zaw Win (2008).
*Acta Cryst.*A**64**, 437–449. [PubMed] - Tanaka, K. & Marumo, F. (1983).
*Acta Cryst.*A**39**, 631–641. - Tanaka, K. & Ōnuki, Y. (2002).
*Acta Cryst.*B**58**, 423–436. [PubMed] - Woodward, P. M., Vogt, T., Cox, D. E., Arulraj, A., Rao, C. N. R., Karen, P. & Cheetham, A. K. (1998).
*Chem. Mater.***10**, 3652–3665. - Zhurov, V. V. & Tanaka, K. (2003). Proceedings of the 28th ISTC Japan Workshop on Frontiers of X-ray Diffraction Technologies in Russia/CIS, pp. 169–178.

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