Incommensurately modulated phase of Rb2CoBr4 at 295K and 200 K

Authors:

Friese, K.; Madariaga, G.; Breczewski, T.

Journal:

Acta Crystallographica, Section B 56 17-21 (2000)

DOI:

https://doi.org/10.1107/s0108768199010629

B-IncStrDB ID: 2782Ekny4Q Entry date: 2010-11-08 Last revision: 2021-12-30

rcb110

Chemical data


Full Name: Rubidium Tetra Bromo Cobaltate [ Help ]

Formula moiety: Rb2CoBr4 [ Help ]

Structural Formula Sum: Br2 Co0.50 Rb [ Help ]

Formula weight: 274.76 Da [ Help ]

Crystallographic data and experimental details


Crystal system: orthorhombic [ Help ]

Space group name (H-M): P n a m [ Help ]

Space group name (Hall): -P 2c -2n [ Help ]

Symmetry operations of the space group: [ Help ]

Operation code Operation in algebraic form
1 x,y,z
2 -x,-y,z+1/2
3 x+1/2,-y+1/2,-z+1/2
4 -x+1/2,y+1/2,-z
5 -x,-y,-z
6 x,y,-z-1/2
7 -x-1/2,y-1/2,z-1/2
8 x-1/2,-y-1/2,z

a: 9.732(3) Å [ Help ]

b: 13.328(4) Å [ Help ]

c: 7.654(3) Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90 ° [ Help ]

Volume: 992.8(6) Å3 [ Help ]

Cell determination reflection Nb.: 1204 [ Help ]

θ(min) for cell determination: 2 ° [ Help ]

θ(max) for cell determination: 40 ° [ Help ]

μ: 27.482 mm-1 [ Help ]

Absorption correction type: gaussian [ Help ]

Absorption correction remarks: XRED (STOE & CIE GmbH, 1998) [ Help ]

Minimum transmission factor: .0239 [ Help ]

Maximum transmission factor: .0692 [ Help ]

Experimental remarks: ? [ Help ]

Refinement details


Total nb. of reflections: 477 [ Help ]

Nb. of observed reflections: 286 [ Help ]

Intense reflections threshold: >2sigma(I) [ Help ]

Refinement based on: Fsqd [ Help ]

Matrix type used for the least-squares: full [ Help ]

R(all): .0778 [ Help ]

R(obs): .0414 [ Help ]

wR(all): .1003 [ Help ]

S(all): .810 [ Help ]

Restrained S(all): .810 [ Help ]

Nb. of reflections: 477 [ Help ]

Nb. of parameters: 40 [ Help ]

Number of restraints: 0 [ Help ]

Refinement of hydrogen atoms: mixed [ Help ]

Weighting scheme: calc [ Help ]

Weighting scheme remarks: w=1/[σ2(Fo2)+(0.0518P)2+0.0000P] where P=(Fo2+2Fc2)/3 [ Help ]

Δ/σ(max): .000 [ Help ]

Δ/σ(mean): .000 [ Help ]

Δρ(max): .663 e_Å-3 [ Help ]

Δρ(min): -.825 e_Å-3 [ Help ]

Extinction method: none [ Help ]

Structural Information


Average Structure: [ Help ]

Atom site label Atom symbol x y z Uiso/equiv
Rb1 Rb .0149(3) .6764(3) .25 .0570(9)
Rb2 Rb .3712(3) .4028(3) .25 .0810(10)
Co1 Co .7742(4) .4231(3) .25 .0390(10)
Br1 Br .0183(3) .4149(3) .25 .0870(10)
Br2 Br .6802(4) .5881(3) .25 .101(2)
Br3 Br .6840(3) .3414(2) .5013(3) .1020(10)

ADP components: [ Help ]

Atom site label U11 U22 U33 U12 U13 U23
Rb1 .043(2) .052(2) .076(2) -.0016(18) .000 .000
Rb2 .046(2) .127(3) .087(2) -.001(3) .000 .000
Co1 .034(2) .041(3) .0400(19) -.002(2) .000 .000
Br1 .036(2) .074(3) .151(3) .011(2) .000 .000
Br2 .052(2) .048(2) .202(4) .011(2) .000 .000
Br3 .0781(18) .165(3) .0627(14) -.042(2) -.0134(13) .0546(17)

rbcobr

Chemical data


Structural Formula Sum: Rb2 Co1 Br4 [ Help ]

Formula weight: 549.5 Da [ Help ]

Crystallographic data and experimental details


Crystal system: orthorhombic [ Help ]

Superspace group name (WJJ): P:Pnam:-1ss [ Help ]

Symmetry operations of the superspace group: [ Help ]

Operation code Operation in algebraic form
1 x1,x2,x3,x4
2 -x1,-x2,x3+1/2,-x4+1/2
3 -x1+1/2,x2+1/2,-x3,-x4+1/2
4 x1+1/2,-x2+1/2,-x3+1/2,x4
5 -x1,-x2,-x3,-x4
6 x1,x2,-x3+1/2,x4+1/2
7 x1+1/2,-x2+1/2,x3,x4+1/2
7 -x1+1/2,x2+1/2,x3+1/2,-x4

a: 9.691(4) Å [ Help ]

b: 13.278(5) Å [ Help ]

c: 7.630(6) Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90 ° [ Help ]

Volume: 981.8(16) Å3 [ Help ]

Z: 4 [ Help ]

Modulation dimension: 1 [ Help ]

Measured independent wave vectors: [ Help ]

Wave vector id q_x q_y q_z
1 0.31 0.0 0.0

Cell determination reflection Nb.: 707 [ Help ]

θ(min) for cell determination: 2.5 ° [ Help ]

θ(max) for cell determination: 45 ° [ Help ]

Cell measurement temperature: 200 K [ Help ]

μ: 27.79 mm-1 [ Help ]

Absorption correction type: gaussian [ Help ]

Absorption correction remarks: XRED (STOE & CIE GmbH, 1998) [ Help ]

Minimum transmission factor: .0239 [ Help ]

Maximum transmission factor: .0692 [ Help ]

Refinement details


Total nb. of reflections: 1849 [ Help ]

Nb. of observed reflections: 309 [ Help ]

Intense reflections threshold: >2sigma(I) [ Help ]

Refinement based on: F [ Help ]

R(all): .0515 [ Help ]

R(obs): .2971 [ Help ]

wR(all): .0375 [ Help ]

S(all): 1.77 [ Help ]

S(obs): .88 [ Help ]

Nb. of reflections: 1849 [ Help ]

Nb. of parameters: 56 [ Help ]

Weighting scheme: sigma [ Help ]

Weighting scheme remarks: w=1/σ2(F) [ Help ]

Δ/σ(max): .0001 [ Help ]

Δ/σ(mean): .0000 [ Help ]

Δρ(max): 5.43 e_Å-3 [ Help ]

Δρ(min): -6.05 e_Å-3 [ Help ]

Extinction method: none [ Help ]

Structural Information


Average Structure: [ Help ]

Atom site label Atom symbol x y z Uiso/equiv Occupancy
Rb1 Rb .0132(4) .6755(3) .25 .038(2) 1
Rb2 Rb .3736(5) .4025(4) .25 .063(2) 1
Co Co .7760(4) .4232(4) .25 .035(2) 1
Br1 Br 1.0196(4) .4160(4) .25 .056(3) 1
Br2 Br .6771(4) .5864(4) .25 .050(3) 1
Br3 Br .6870(4) .3395(3) .5003(6) .062(2) 1

ADP components: [ Help ]

Atom site label U11 U22 U33 U12 U13 U23
Rb1 .033(2) .036(2) .043(3) -.002(2) 0 0
Rb2 .045(3) .098(5) .044(4) .007(3) 0 0
Co .037(3) .046(4) .020(3) .003(3) 0 0
Br1 .035(3) .066(4) .068(6) .003(3) 0 0
Br2 .033(3) .045(3) .071(8) .005(3) 0 0
Br3 .063(3) .090(5) .033(2) -.030(4) -.005(3) .028(3)

Fourier Wave Vectors (explicit: q_x,q_y,q_z or coefficients: q_1,q_2,...): [ Help ]

Wave vector code q_x q_y q_z
1 0.31 0.0 0.0

Definition of the displacive (translational) Fourier series: [ Help ]

Modulation code Atom site label Displacement axis Wave vector code
Rb1x1 Rb1 x 1
Rb1y1 Rb1 y 1
Rb1z1 Rb1 z 1
Rb2x1 Rb2 x 1
Rb2y1 Rb2 y 1
Rb2z1 Rb2 z 1
Cox1 Co x 1
Coy1 Co y 1
Coz1 Co z 1
Br1x1 Br1 x 1
Br1y1 Br1 y 1
Br1z1 Br1 z 1
Br2x1 Br2 x 1
Br2y1 Br2 y 1
Br2z1 Br2 z 1
Br3x1 Br3 x 1
Br3y1 Br3 y 1
Br3z1 Br3 z 1

Displacive (translational) Fourier coefficients: [ Help ]

Modulation code Sine coefficient Cosine coefficient
Rb1x1 0.0 0.0
Rb1y1 0.0 0.0
Rb1z1 0.016(2) -0.002(2)
Rb2x1 0.0 0.0
Rb2y1 0.0 0.0
Rb2z1 -0.012(2) 0.013(2)
Cox1 0.0 0.0
Coy1 0.0 0.0
Coz1 -0.009(2) -0.005(2)
Br1x1 0.0 0.0
Br1y1 0.0 0.0
Br1z1 -0.042(2) -0.006(2)
Br2x1 0.0 0.0
Br2y1 0.0 0.0
Br2z1 -0.011(3) -0.062(2)
Br3x1 0.008(4) -0.013(1)
Br3y1 0.002(1) 0.0315(7)
Br3z1 -0.005(2) 0.020(1)