Research/Sitter/MAGNDATA / 1.0.48_MnSe2.mcif

MnSe₂

MAGNDATA entry 1.0.48 · source

d-wave 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. d-wave: the splitting changes sign twice around the Fermi surface (2 nodal planes).

Spin group ²m²m¹m: each symmetry marked ¹ keeps every spin, ² swaps up and down.

ordered ≤ 49 K (−224 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 10 properties

Magnetic group	P c a′ 2₁′ BNS 29.102
Parent space group	P a 3 No. 205
Spins	collinear · 2 nodal planes · net moment 0 μ_B per cell
Propagation	[1/3 0 0] · [0 0 0] 1k
Cell	a 19.2825 · b 6.4275 · c 6.4275 Å · α 90° · β 90° · γ 90°
Transition	49 K (−224 °C)
Measured at	1.8 K
Magnetic ions	Mn
Largest moment component	2.8 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 P c a′ 2₁′ →

Atom sites · 9 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Mn1_1	Mn	0	0	0	2.8	0	0	2.8
Mn1_2	Mn	0.3333	0	0	−2.8	0	0	2.8
Mn1_3	Mn	0.5	0	0.5	−2.8	0	0	2.8
Se1_1	Se	0.1312	0.3936	0.3936
Se1_2	Se	0.8688	0.8936	0.1064
Se1_3	Se	0.4645	0.3936	0.3936
Se1_4	Se	0.3688	0.6064	0.8936
Se1_5	Se	0.2021	0.8936	0.1064
Se1_6	Se	0.6312	0.1064	0.6064

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

T. Chattopadhyay et al. Solid State Communications (1987) · doi:10.1016/0038-1098(87)90067-6

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.0.48_MnSe2.mcif from MAGNDATA · entry page

sha256 of this copy: 762ded0c27e0a21582032ff067a725da72a4038b2ad4fede24722d9550b1db51
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.0.48_MnSe2.mcif.