MAGNDATA - Collection of Magnetic Structures

MAGNDATA

Collection of Magnetic Structures

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

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Magnetic structure with all atoms

Magnetic structure with only magnetic atoms

N	(x,y,z)	Seitz notation
1	x,y,z,+1	{ 1 \| 0 }
2	-x+1/2,-y,z+1/2,+1	{ 2₀₀₁ \| 1/2 0 1/2 }
3	-x,-y,-z,-1	{ -1' \| 0 }
4	x+1/2,y,-z+1/2,-1	{ m'₀₀₁ \| 1/2 0 1/2 }

N	(x,y,z)	Seitz notation
1	x,y,z,+1	1
2	-x,-y,z,+1	2₀₀₁
3	-x,-y,-z,-1	-1'
4	x,y,-z,-1	m'₀₀₁

Label	Atom type	x	y	z	Multiplicity
Li1_1	Li	0.00000	0.00000	0.00000	2
Li1_2	Li	0.00000	0.50000	0.00000	2
P1	P	0.09450	0.25000	0.41900	4
O1	O	0.09860	0.25000	0.74300	4
O2	O	0.45450	0.25000	0.20300	4
O3_1	O	0.16690	0.04630	0.28260	4
O3_2	O	0.83310	0.54630	0.71740	4

Atom	x	y	z	Symmetry constraints on M	M_y	M_z
1	0.27800	0.25000	0.98000	m_x,m_y,m_z	3.51000	0.43000
2	0.22200	0.75000	0.48000	-m_x,-m_y,m_z	-3.51000	0.43000
3	0.72200	0.75000	0.02000	-m_x,-m_y,-m_z	-3.51000	-0.43000
4	0.77800	0.25000	0.52000	m_x,m_y,-m_z	3.51000	-0.43000

Atom	x	y	z
1	0.00000	0.00000	0.00000
2	0.50000	0.00000	0.50000

Atom	x	y	z
1	0.00000	0.50000	0.00000
2	0.50000	0.50000	0.50000

Atom	x	y	z
1	0.09450	0.25000	0.41900
2	0.40550	0.75000	0.91900
3	0.90550	0.75000	0.58100
4	0.59450	0.25000	0.08100

Atom	x	y	z
1	0.09860	0.25000	0.74300
2	0.40140	0.75000	0.24300
3	0.90140	0.75000	0.25700
4	0.59860	0.25000	0.75700

Atom	x	y	z
1	0.45450	0.25000	0.20300
2	0.04550	0.75000	0.70300
3	0.54550	0.75000	0.79700
4	0.95450	0.25000	0.29700

Atom	x	y	z
1	0.16690	0.04630	0.28260
2	0.33310	0.95370	0.78260
3	0.83310	0.95370	0.71740
4	0.66690	0.04630	0.21740

Atom	x	y	z
1	0.83310	0.54630	0.71740
2	0.66690	0.45370	0.21740
3	0.16690	0.45370	0.28260
4	0.33310	0.54630	0.78260

Reference: E. Fogh, O. Zaharko, J. Schefer, C. Niedermayer, S. Holm-Dahlin, M.K. Sorensen, A.B. Kristensen, N.H. Andersen, D. Vaknin, N.B. Christensen and R. Toft-Petersen, Physical Review B (2019) 99 104421.
DOI: 10.1103/physrevb.99.104421
Atomic positions from: same reference

Parent space group (paramagnetic phase): Pnma (#62)
Propagation vector: k1 (0, 0, 0)

Transition Temperature: 21.6 K
Experiment Temperature: 10 K

Lattice parameters of the magnetic unit cell:
10.20000 5.92000 4.70000 90.00 90.00 90.00
Transformation from parent structure: (a,b,c;0,0,0)
    [View matrix form]

BNS Magnetic Space Group: P2₁/c' (#14.78) (non-standard)
    [View symmetry operations]
Transformation to a standard setting: (-b,-c,a;0,0,0)
    [View matrix form]
Systematic absences for this Magnetic Space Group via

Magnetic Point Group: 2/m' (5.4.15)
    [View symmetry operations]
Symmetry-adapted form of material tensors via
Symmetry-adapted form of material tensors for domain-related equivalent structures via

Positions and magnetic moments 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]                                             Use MVISUALIZE to:
     [Show all the atoms]

Label	Atom type	x	y	z	Multiplicity	Symmetry constraints on M	M_x	M_y	M_z	\|M\|
Co1	Co	0.27800	0.25000	0.98000	4	m_x,m_y,m_z	0.0	3.51	0.43	3.54

Atom	x	y	z	Symmetry constraints on M	M_y	M_z
1	0.27800	0.25000	0.98000	m_x,m_y,m_z	3.51000	0.43000
2	0.22200	0.75000	0.48000	-m_x,-m_y,m_z	-3.51000	0.43000
3	0.72200	0.75000	0.02000	-m_x,-m_y,-m_z	-3.51000	-0.43000
4	0.77800	0.25000	0.52000	m_x,m_y,-m_z	3.51000	-0.43000

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

Active Irreps:

label	dim. small irrep	dim. full irrep	action	number of modes
mGM2-	1	1	primary	1
mGM1-	1	1	primary	2

Comments:

NSD
Position structure from a determination at 30K
Co moment: 3.54(5)
Apparently the proposed small canting that lowers the symmetry of the model is not the result of a least-squares fit of the NSD data, but from the comparison of two particular peak intensities.
See #0.193 and #0.383 for a different model of this structure with higher symmetry and a single irrep involved
See #0.384 for a model with rather different symmetry also involving two irreps

Comments (symmetry):

1k magnetic structure
Two irreps as primary: two order parameters are involved in the sense of Landau theory, one of them being very small.
The magnetic point group of the structure is 2_z/m'_z
Assumedly the system is supoosed to have a weak FM component along b, which would further reduce the point group to m’_z

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

LiCoPO4 (#0.385)

LiCoPO₄ (#0.385)