Research/Sitter/MAGNDATA / 0.115_MnCO3.mcif

MnCO₃

MAGNDATA entry 0.115 · source

altermagnet

No net magnetisation, yet the electron bands are spin-split: the up and down spin sublattices are related only by a rotation or mirror, never by a shift or inversion.

Spin group ¹3̄²m: each symmetry marked ¹ keeps every spin, ² swaps up and down.

ordered ≤ 32 K (−241 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	C 2/c BNS 15.85
Point group	2/m
Parent space group	R 3c No. 167
Spins	collinear · 3 nodal planes · net moment 0 μ_B per cell
Propagation	[0 0 0] 1k
Cell	a 4.772 · b 4.772 · c 15.637 Å · α 90° · β 90° · γ 120°
Transition	32 K (−241 °C)
Measured at	4.2 K
Magnetic ions	Mn
Largest moment component	2 μ_B
Method	NSD

Symmetry

Stereogram of the magnetic point group: each operation applied to one direction. Filled = upper hemisphere, ring = lower; red operations include time reversal. Lines are mirrors; polygons are 2/3/4/6-fold axes; the centre ring is inversion.

Every structure in C 2/c →

Atom sites · 4 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Mn1	Mn	0	0	0	1	2	0	1.7321
C1	C	0	0	0.25
O1_1	O	0.2697	0	0.25
O1_2	O	0	0.2697	0.25

Moment components are along the crystal axes a, b, c (μ_B), as magCIF writes them. Symmetry generates the rest of the cell from these sites.

Source

P.J. Brown et al. PROC. PHYS. SOC. (1967) · doi:10.1088/0370-1328/92/1/319

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 0.115_MnCO3.mcif from MAGNDATA · entry page

sha256 of this copy: 429b3ce03b0ed8bf6ea9306ffa56948928635ea3af0ebcd3d910eeda37d4c0ec
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 0.115_MnCO3.mcif.