Incommensurately modulated structures of the M1/8Pr5/8MoO4 (M = Li, Na, K) scheelites

Authors:

Morozov, Vladimir A.; Deyneko, Dina V.; Filatova, Darya G.; Belik, Alexei A.; Basovich, Olga M.; Khaikina, Elena G.; Lazoryak, Bogdan I.

Journal:

Acta Crystallographica Section B 82 120-130 (2026)

DOI:

https://doi.org/10.1107/S2052520626000375

B-IncStrDB ID: L8zZeSPwZg1 Entry date: 2026-02-04 Last revision: 2026-05-19

NaPr5Mo8O32

Chemical data


Common Name: Na0.125 Pr0.625 Mo1 O4 [ Help ]

Formula moiety: Na0.125 Pr0.625 Mo O4 [ Help ]

Structural Formula: Na0.125 Pr0.625 Mo1 O4 [ Help ]

Formula analytical: Na0.125 Pr0.625 Mo1 O4 [ Help ]

Formula (IUPAC): Na0.125 Pr0.625 Mo1 O4 [ Help ]

Structural Formula Sum: Na0.125 Pr0.625 Mo O4 [ Help ]

Formula weight: 250.9 Da [ Help ]

Absolute configuration: . [ Help ]

Crystallographic data and experimental details


Crystal system: monoclinic [ Help ]

Superspace group name: I2/b(αβ0)00 [ Help ]

Symmetry operations of the superspace group: [ Help ]

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

a: 5.30752(3) Å [ Help ]

b: 5.30900(3) Å [ Help ]

c: 11.75478(3) Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90.0084(9) ° [ Help ]

Volume: 331.222(3) Å3 [ Help ]

Modulation dimension: 1 [ Help ]

Measured independent wave vectors: [ Help ]

Wave vector id q_x q_y q_z
1 0.578340 0.837694 0.000000

Z: 4 [ Help ]

Cell measurement temperature: 293 K [ Help ]

μ: 12.573 mm-1 [ Help ]

Absorption correction remarks: (Jana2000; Petricek, Dusek & Palatinus, 2000) [ Help ]

Refinement details


R(obs): 0.0340 [ Help ]

wR(obs): 0.0248 [ Help ]

R(all): 0.0619 [ Help ]

wR(all): 0.0276 [ Help ]

S(all): 0.98 [ Help ]

Nb. of parameters: 60 [ Help ]

Number of restraints: 0 [ Help ]

Number of constraints: 2 [ Help ]

Weighting scheme: sigma [ Help ]

Δ/σ(max): 0.01875 [ Help ]

Δ/σ(mean): 0.1446 [ Help ]

Δρ(max): 2.35 e_Å-3 [ Help ]

Δρ(min): -4.99 e_Å-3 [ Help ]

Structural Information


Average Structure: [ Help ]

Atom site label Atom symbol x y z ADP type Uiso/equiv Symmetry multiplicity Occupancy Coords from (d)iffraction or (c)alculated Coords restraints or constraints Disordered cluster Disordered group
Pr Pr 0.5 0.25 0.8734(5) Uiso 0.0053(3) 4 0.625 d . . .
Na Na 0.5 0.25 0.8734(5) Uiso 0.0053(3) 4 0.125 d . . .
Mo Mo 0.5 0.25 0.3758(4) Uiso 0.0114(3) 4 1 d . . .
O1 O 0.754(3) 0.396(3) 0.4568(12) Uiso 0.020(4) 8 1 d . . .
O2 O 0.858(3) 0.486(2) 0.2087(12) Uiso 0.010(3) 8 1 d . . .

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

Wave vector code q_1
1 1

Average occupancy: [ Help ]

Atom site label Occupancy
Pr 0.625
Na 0.125

Definition of the occupation Fourier series: [ Help ]

Modulation code Atom site label Wave vector code
Pro1 Pr 1
Nao1 Na 1

Occupation Fourier coefficients: [ Help ]

Modulation code Cosine coefficient Sine coefficient
Pro1 0.345(2) 0
Nao1 -0.0689(4) 0

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

Modulation code Atom site label Displacement axis Wave vector code
Prx1 Pr x 1
Pry1 Pr y 1
Prz1 Pr z 1
Nax1 Na x 1
Nay1 Na y 1
Naz1 Na z 1
Mox1 Mo x 1
Moy1 Mo y 1
Moz1 Mo z 1
O1x1 O1 x 1
O1y1 O1 y 1
O1z1 O1 z 1
O2x1 O2 x 1
O2y1 O2 y 1
O2z1 O2 z 1

Displacive (translational) Fourier coefficients: [ Help ]

Modulation code Cosine coefficient Sine coefficient
Prx1 0 0.0130(4)
Pry1 0 0.0081(4)
Prz1 0.0017(5) 0
Nax1 0 0.0130(4)
Nay1 0 0.0081(4)
Naz1 0.0017(5) 0
Mox1 0 -0.0070(4)
Moy1 0 -0.0105(4)
Moz1 0.0016(4) 0
O1x1 0 -0.013(2)
O1y1 0 0
O1z1 0.0077(8) 0.0070(9)
O2x1 0 -0.0129(18)
O2y1 0.018(2) -0.0176(19)
O2z1 -0.0088(8) 0

KPr5MoO32

Chemical data


Common Name: K0.145 Pr0.618 Mo1 O4 [ Help ]

Formula moiety: K0.145 Mo1 O4 Pr0.618 [ Help ]

Structural Formula: K0.145 Pr0.618 Mo1 O4 [ Help ]

Formula analytical: K0.145 Pr0.618 Mo1 O4 [ Help ]

Formula (IUPAC): K0.145 Pr0.618 Mo1 O4 [ Help ]

Structural Formula Sum: K0.145 Mo1 O4 Pr0.618 [ Help ]

Formula weight: 252.7 Da [ Help ]

Absolute configuration: . [ Help ]

Crystallographic data and experimental details


Crystal system: monoclinic [ Help ]

Superspace group name: I2/b(αβ0)00 [ Help ]

Symmetry operations of the superspace group: [ Help ]

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

a: 5.318570(10) Å [ Help ]

b: 5.339590(10) Å [ Help ]

c: 11.87729(3) Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90.0509(2) ° [ Help ]

Volume: 337.3028(12) Å3 [ Help ]

Modulation dimension: 1 [ Help ]

Measured independent wave vectors: [ Help ]

Wave vector id q_x q_y q_z
1 0.566419 0.836554 0.000000

Z: 4 [ Help ]

Cell measurement temperature: 293 K [ Help ]

μ: 12.367 mm-1 [ Help ]

Absorption correction remarks: (Jana2000; Petricek, Dusek & Palatinus, 2000) [ Help ]

Refinement details


R(obs): 0.0400 [ Help ]

wR(obs): 0.0237 [ Help ]

R(all): 0.0476 [ Help ]

wR(all): 0.0241 [ Help ]

S(all): 1.41 [ Help ]

Nb. of parameters: 69 [ Help ]

Number of restraints: 4 [ Help ]

Number of constraints: 4 [ Help ]

Weighting scheme: sigma [ Help ]

Δ/σ(max): 0.01823 [ Help ]

Δ/σ(mean): 0.0167 [ Help ]

Δρ(max): 2.62 e_Å-3 [ Help ]

Δρ(min): -3.01 e_Å-3 [ Help ]

Structural Information


Average Structure: [ Help ]

Atom site label Atom symbol x y z ADP type Uiso/equiv Symmetry multiplicity Occupancy Coords from (d)iffraction or (c)alculated Coords restraints or constraints Disordered cluster Disordered group
Pr1 Pr 0.5 0.25 0.8708(3) Uiso 0.0060(2) 4 0.3541(3) d . . .
K K 0.5 0.25 0.8708(3) Uiso 0.0060(2) 8 0.0724(5) d . . .
Mo Mo 0.5 0.25 0.37519(17) Uiso 0.0159(3) 4 1 d . . .
O1 O 0.7459(7) 0.3911(7) 0.4560(4) Uiso 0.0159(14) 8 1 d . . .
O2 O 0.3593(7) 0.4901(7) 0.2929(4) Uiso 0.0109(12) 8 1 d . . .
Pr2 Pr 0.5 0.25 0.8708(3) Uiso 0.0060(2) 8 0.1321 d . . .

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

Wave vector code q_1
1 1
2 2

Occupation crenel coefficients: [ Help ]

Atom site label Center (x0) Width
Pr1 0.5 0.3541(3)
K 0.28675(8) 0.0724(5)
Pr2 0.1845(3) 0.1322

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

Modulation code Atom site label Displacement axis Wave vector code
Pr1x1 Pr1 x 1
Pr1y1 Pr1 y 1
Pr1z1 Pr1 z 1
Pr1x2 Pr1 x 2
Pr1y2 Pr1 y 2
Pr1z2 Pr1 z 2
Kx1 K x 1
Ky1 K y 1
Kz1 K z 1
Kx2 K x 2
Ky2 K y 2
Kz2 K z 2
Mox1 Mo x 1
Moy1 Mo y 1
Moz1 Mo z 1
Mox2 Mo x 2
Moy2 Mo y 2
Moz2 Mo z 2
O1x1 O1 x 1
O1y1 O1 y 1
O1z1 O1 z 1
O1x2 O1 x 2
O1y2 O1 y 2
O1z2 O1 z 2
O2x1 O2 x 1
O2y1 O2 y 1
O2z1 O2 z 1
O2x2 O2 x 2
O2y2 O2 y 2
O2z2 O2 z 2
Pr2x1 Pr2 x 1
Pr2y1 Pr2 y 1
Pr2z1 Pr2 z 1
Pr2x2 Pr2 x 2
Pr2y2 Pr2 y 2
Pr2z2 Pr2 z 2

Displacive (translational) Fourier coefficients: [ Help ]

Modulation code Cosine coefficient Sine coefficient
Pr1x1 0 -0.0134(2)
Pr1y1 0 -0.0069(2)
Pr1z1 -0.0101(4) 0
Pr1x2 0 -0.0005(5)
Pr1y2 0 0.0034(5)
Pr1z2 -0.0098(4) 0
Kx1 0 -0.0134(2)
Ky1 0 -0.0069(2)
Kz1 -0.0101(4) 0
Kx2 0 -0.0005(5)
Ky2 0 0.0034(5)
Kz2 -0.0098(4) 0
Mox1 0 0.0085(3)
Moy1 0 0.0164(2)
Moz1 -0.00415(16) 0
Mox2 0 -0.0011(6)
Moy2 0 -0.0032(6)
Moz2 -0.0014(3) 0
O1x1 -0.0059(12) 0
O1y1 0.0104(11) 0
O1z1 -0.0126(5) -0.0088
O1x2 0.009(2) -0.009(2)
O1y2 -0.007(3) 0.012(2)
O1z2 -0.0023(10) 0.0036(9)
O2x1 0.0084(12) 0.0129(12)
O2y1 -0.0289(12) 0.0264(12)
O2z1 -0.0128(5) -0.0018(5)
O2x2 -0.009(2) 0.006(2)
O2y2 0.003(2) 0.012(2)
O2z2 0.0025(9) 0.0044(9)
Pr2x1 0 -0.0134(2)
Pr2y1 0 -0.0069(2)
Pr2z1 -0.0101(4) 0
Pr2x2 0 -0.0005(5)
Pr2y2 0 0.0034(5)
Pr2z2 -0.0098(4) 0

Li-scheelite

Chemical data


Common Name: Li0.125 Pr0.625 Mo1 O4 [ Help ]

Formula moiety: Li0.125 Mo1 O4 Pr0.625 [ Help ]

Structural Formula: Li0.125 Pr0.625 Mo1 O4 [ Help ]

Formula analytical: Li0.125 Pr0.625 Mo1 O4 [ Help ]

Formula (IUPAC): Li0.125 Pr0.625 Mo1 O4 [ Help ]

Structural Formula Sum: Li0.125 Pr0.625 Mo1 O4 [ Help ]

Formula weight: 246.5 Da [ Help ]

Absolute configuration: . [ Help ]

Crystallographic data and experimental details


Crystal system: monoclinic [ Help ]

Superspace group name: I2/b(αβ0)00 [ Help ]

Symmetry operations of the superspace group: [ Help ]

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

a: 5.302630(10) Å [ Help ]

b: 5.297920(10) Å [ Help ]

c: 11.75179(2) Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90.0184(4) ° [ Help ]

Volume: 330.1420(10) Å3 [ Help ]

Modulation dimension: 1 [ Help ]

Measured independent wave vectors: [ Help ]

Wave vector id q_x q_y q_z
1 0.568641 0.835383 0.000000

Z: 4 [ Help ]

Cell measurement temperature: 293 K [ Help ]

μ: 12.497 mm-1 [ Help ]

Absorption correction remarks: (Jana2000; Petricek, Dusek & Palatinus, 2000) [ Help ]

Refinement details


R(obs): 0.0391 [ Help ]

wR(obs): 0.0232 [ Help ]

R(all): 0.0589 [ Help ]

wR(all): 0.0241 [ Help ]

S(all): 1.35 [ Help ]

Nb. of parameters: 52 [ Help ]

Number of restraints: 0 [ Help ]

Number of constraints: 2 [ Help ]

Weighting scheme: sigma [ Help ]

Δ/σ(max): 0.0232 [ Help ]

Δ/σ(mean): 0.1435 [ Help ]

Δρ(max): 2.77 e_Å-3 [ Help ]

Δρ(min): -4.70 e_Å-3 [ Help ]

Structural Information


Average Structure: [ Help ]

Atom site label Atom symbol x y z ADP type Uiso/equiv Symmetry multiplicity Occupancy Coords from (d)iffraction or (c)alculated Coords restraints or constraints Disordered cluster Disordered group
Pr Pr 0.5 0.25 0.8737(3) Uiso 0.0069(2) 4 0.625 d . . .
Li Li 0.5 0.25 0.8737(3) Uiso 0.0069(2) 4 0.125 d . . .
Mo Mo 0.5 0.25 0.3745(3) Uiso 0.0145(2) 4 1 d . . .
O1 O 0.7473(12) 0.3894(10) 0.4587(6) Uiso 0.0188(15) 8 1 d . . .
O2 O 0.8498(9) 0.4892(11) 0.2068(6) Uiso 0.0158(15) 8 1 d . . .

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

Wave vector code q_1
1 1

Average occupancy: [ Help ]

Atom site label Occupancy
Pr 0.625
Li 0.125

Definition of the occupation Fourier series: [ Help ]

Modulation code Atom site label Wave vector code
Pro1 Pr 1
Lio1 Li 1

Occupation Fourier coefficients: [ Help ]

Modulation code Cosine coefficient Sine coefficient
Pro1 -0.3523(12) 0
Lio1 0.0705(2) 0

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

Modulation code Atom site label Displacement axis Wave vector code
Prx1 Pr x 1
Pry1 Pr y 1
Prz1 Pr z 1
Lix1 Li x 1
Liy1 Li y 1
Liz1 Li z 1
Mox1 Mo x 1
Moy1 Mo y 1
Moz1 Mo z 1
O1x1 O1 x 1
O1y1 O1 y 1
O1z1 O1 z 1
O2x1 O2 x 1
O2y1 O2 y 1
O2z1 O2 z 1

Displacive (translational) Fourier coefficients: [ Help ]

Modulation code Cosine coefficient Sine coefficient
Prx1 0 -0.0133(3)
Pry1 0 -0.0094(3)
Prz1 -0.0028(3) 0
Lix1 0 -0.0133(3)
Liy1 0 -0.0094(3)
Liz1 -0.0028(3) 0
Mox1 0 0.0086(3)
Moy1 0 0.0110(2)
Moz1 -0.00224(19) 0
O1x1 -0.0049(15) 0.0056(14)
O1y1 0.0037(12) 0.0040(13)
O1z1 -0.0085(5) -0.0070(5)
O2x1 0 0.0110(12)
O2y1 -0.0211(14) 0.0151(13)
O2z1 0.0081(5) 0.0028(6)