Research/Sitter/MAGNDATA / 1.1.165_MnO2.mcif

MnO₂

MAGNDATA entry 1.1.165 · source

incommensurate spin-density wave

Incommensurate: the magnetic pattern repeats every so many cells, but not a whole number of them, so it never lines up with the crystal lattice. Here it's a spin-density wave: the size of the spin swells and shrinks as you move along.

ordered ≤ 92 K (−181 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	Pnnm1′(0,0,γ)s00s
Point group	mmm1′
Parent space group	P n n m No. 58
Repeats every	3.37 cells along c (not a whole number: that's what incommensurate means)
Propagation	[0 0 0.297] 1k
Cell	a 4.39945 · b 4.38503 · c 2.87249 Å · α 90° · β 90° · γ 90°
Transition	92 K (−181 °C)
Measured at	12 K
Magnetic ions	Mn
Largest moment component	3.113 μ_B
Method	NPD

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 Pnnm1′(0,0,γ)s00s →

Atom sites · 2 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Mn1	Mn	0	0	0
O1	O	0.3063	0.303	0

Incommensurate: the moments are modulated; the picture evaluates each atom's Fourier series at its own phase.

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. Fabrykiewicz et al. Acta Cryst. A (2019) · doi:10.1107/S2053273319013408

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.165_MnO2.mcif from MAGNDATA · entry page

sha256 of this copy: f80dac2b95367a813cbf0241694cf7e68d6f529673be7fe37b5f179c475b6f03
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.165_MnO2.mcif.