MAGNDATA - Collection of Magnetic Structures

Magnetic structure with only magnetic atoms

N	(x,y,z)	Seitz notation
1	x1,x2,x3,x4,+1	{ 1 \| 0 }
2	-x1,x2+1/2,-x3,-x4,+1	{ 2₀₁₀ \| 0 1/2 0 0 }
(0,0,0,1/2)' + set click here to show and hide
3	x1,x2,x3,x4+1/2,-1	{ 1' \| 0 0 0 1/2 }
4	-x1,x2+1/2,-x3,-x4+1/2,-1	{ 2'₀₁₀ \| 0 1/2 0 1/2 }

N	(x,y,z)	Seitz notation
1	x,y,z,+1	1
2	-x,y,-z,+1	2₀₁₀
1' + set click here to show and hide
3	x,y,z,-1	1'
4	-x,y,-z,-1	2'₀₁₀

Label	Atom type	x	y	z	Multiplicity
As1_1	As	0.1992	0.25	0.5857	2
As1_2	As	0.3008	0.75	0.0857	2

Atom	Magnetic moment Fourier Cos coeffs	Magnetic moment Fourier Sin coeffs
Symmetry constraints	Numerical values	Symmetry constraints	Numerical values
x	y	z	x	y	z	x	y	z	x	y	z
Cr1_1	M_xcos1	M_ycos1	M_zcos1	0.48(4)	3.113(6)	0.28(6)	M_xsin1	M_ysin1	M_zsin1	-2.59(2)	0.55(3)	-1.72(4)
Cr1_2	M_xcos1	M_ycos1	M_zcos1	2.46(2)	0.13(4)	-1.98(3)	M_xsin1	M_ysin1	M_zsin1	-0.04(5)	-3.151(5)	-0.26(5)

Atom	x	y	z
1	0.00000	0.25000	0.20340
2	0.00000	0.75000	0.79660

Atom	Magnetic moment Fourier Cos coeffs	Magnetic moment Fourier Sin coeffs
Symmetry constraints	Numerical values	Symmetry constraints	Numerical values
x	y	z	x	y	z	x	y	z	x	y	z
1	M_xcos1	M_ycos1	M_zcos1	0.48000	3.11300	0.28000	M_xsin1	M_ysin1	M_zsin1	-2.59000	0.55000	-1.72000
2	-M_xcos1	M_ycos1	-M_zcos1	-0.48000	3.11300	-0.28000	M_xsin1	-M_ysin1	M_zsin1	-2.59000	-0.55000	-1.72000

Atom	x	y	z
1	0.50000	0.75000	0.70340
2	0.50000	0.25000	0.29660

Atom	Magnetic moment Fourier Cos coeffs	Magnetic moment Fourier Sin coeffs
Symmetry constraints	Numerical values	Symmetry constraints	Numerical values
x	y	z	x	y	z	x	y	z	x	y	z
1	M_xcos1	M_ycos1	M_zcos1	2.46000	0.13000	-1.98000	M_xsin1	M_ysin1	M_zsin1	-0.04000	-3.15100	-0.26000
2	-M_xcos1	M_ycos1	-M_zcos1	-2.46000	0.13000	1.98000	M_xsin1	-M_ysin1	M_zsin1	-0.04000	3.15100	-0.26000

Atom	x	y	z
1	0.19920	0.25000	0.58570
2	0.80080	0.75000	0.41430

Atom	x	y	z
1	0.30080	0.75000	0.08570
2	0.69920	0.25000	0.91430

Reference: A. Eich, A. Grzechnik, Y. Su, B. Ouladdiaf, D. Sheptyakov, T. Wolf, V. Petricek, H. Shahed, K. Friese, Acta Cryst. B (2023) 79 473 - 481
DOI: 10.1107/S205252062300817X
Atomic positions from: same reference

Parent space group (paramagnetic phase): Pnma (#62)
Propagation vector: k1 (0.000000, 0.000000, 0.353000)

Transition Temperature: 267 K
Experiment Temperature: 2 K

Lattice parameters of the basic unit cell:
5.6432 3.5862 6.2038 90 90 90
Transformation from parent structure: (a,b,c;0,0,0)
    [View matrix form]

Magnetic Superspace Group: P21.1â€™(α0γ)0s
    [View symmetry operations]

Magnetic Point Group: 2.1' (3.2.7)
    [View symmetry operations]
Symmetry-adapted form of material tensors via

Average positions, magnetic moments and magnetic modulations of symmetry independent atoms:
From now on, magnetic atoms are in boldface and colored in red. Magnetic moments are expressed in units of μB

     [Show only magnetic atoms]
     [Show all the atoms]

Average atomic positions of symmetry independent atoms

Label	Atom type	x	y	z	Multiplicity
Cr1_1	Cr	0	0.25	0.2034	2
Cr1_2	Cr	0.5	0.75	0.7034	2

Magnetic moment modulation parameters of symmetry independent atoms

Wave vector 1

Atom	Magnetic moment Fourier Cos coeffs						Magnetic moment Fourier Sin coeffs
	Symmetry constraints			Numerical values			Symmetry constraints			Numerical values
	x	y	z	x	y	z	x	y	z	x	y	z
Cr1_1	M_xcos1	M_ycos1	M_zcos1	0.48(4)	3.113(6)	0.28(6)	M_xsin1	M_ysin1	M_zsin1	-2.59(2)	0.55(3)	-1.72(4)
Cr1_2	M_xcos1	M_ycos1	M_zcos1	2.46(2)	0.13(4)	-1.98(3)	M_xsin1	M_ysin1	M_zsin1	-0.04(5)	-3.151(5)	-0.26(5)

Atom	x	y	z
1	0.00000	0.25000	0.20340
2	0.00000	0.75000	0.79660

Atom	Magnetic moment Fourier Cos coeffs	Magnetic moment Fourier Sin coeffs
Symmetry constraints	Numerical values	Symmetry constraints	Numerical values
x	y	z	x	y	z	x	y	z	x	y	z
1	M_xcos1	M_ycos1	M_zcos1	0.48000	3.11300	0.28000	M_xsin1	M_ysin1	M_zsin1	-2.59000	0.55000	-1.72000
2	-M_xcos1	M_ycos1	-M_zcos1	-0.48000	3.11300	-0.28000	M_xsin1	-M_ysin1	M_zsin1	-2.59000	-0.55000	-1.72000

Atom	x	y	z
1	0.50000	0.75000	0.70340
2	0.50000	0.25000	0.29660

Atom	Magnetic moment Fourier Cos coeffs	Magnetic moment Fourier Sin coeffs
Symmetry constraints	Numerical values	Symmetry constraints	Numerical values
x	y	z	x	y	z	x	y	z	x	y	z
1	M_xcos1	M_ycos1	M_zcos1	2.46000	0.13000	-1.98000	M_xsin1	M_ysin1	M_zsin1	-0.04000	-3.15100	-0.26000
2	-M_xcos1	M_ycos1	-M_zcos1	-2.46000	0.13000	1.98000	M_xsin1	-M_ysin1	M_zsin1	-0.04000	3.15100	-0.26000

[Show all magnetic atoms in unit cell and their moment relations]

Active Irreps:

label	dim. small irrep	dim. full irrep	direction	action	number of modes
mLD3	1	2	general	primary	8
mLD4	1	2	general	primary	4

Comments:

NSD and NPD
See entry 1.1.24 for another model for this structure with a different higher symmetry, which is claimed to be erroneous in the report of this one.
Other possible model candidates with different MSSGs were also tested. This is the one, which yielded the best agreement in the refinement.
The values of the modulation amplitudes in the article differ from those in the accompanying magnetic CIF file, in particular the values for the cosine and sine modulations seem to be interchanged. The values in the CIF file have been assumed correct.

Comments (symmetry):

1k incommensurate magnetic structure
Two irreps are involved, they are same s those present in the model in 1.1.24. The difference here is that the two irreps are not combined in quadrature, with a fixed pi/2 shift of the two modulation phases, but their phase shift is not forced by symmetry. This splits the Cr sites into two independent ones.
The magnetic moments of the two independent Cr sites have approximately equal modulus of 3.16(3 along their modulations.

Bilbao Crystallographic Server
http://www.cryst.ehu.es

For comments, please mail to
cryst@wm.lc.ehu.es

MAGNDATA: A Collection of magnetic structures with portable cif-type files

CrAs (#1.1.152)