Chromium(II) selenide

Chromium(II) selenide is an inorganic compound with the chemical formula CrSe. It crystalizes in a hexagonal structure with space group P6₃/mmc.^[3] It is one of many related chromium-selenium phases, including Cr₂Se₃, as well as Cr₇Se₈, Cr₃Se₄, Cr_0.68Se, and Cr₅Se₈.^[3] The compound has been described as an antiferromagnet, but its inverse magnetic susceptibility does not match the behavior expected for an antiferromagnet according to the Curie–Weiss law.^[1] One suggestion was that the Néel temperature is at 320 K, as the temperature where the compound has maximum specific heat.^[4] When synthesized as single atomic layer, CrSe is ferromagnetic, with a Curie Temperature of around 280 K.^[5]

Chromium(II) selenide

Names
IUPAC name Chromium(2+) selenide
Identifiers
CAS Number	12053-13-3
3D model (JSmol)	Interactive image
ChemSpider	57269572
ECHA InfoCard	100.031.805
EC Number	234-999-1
PubChem CID	82886
CompTox Dashboard (EPA)	DTXSID001014274
InChI InChI=1S/Cr.Se Key: UVZCKRKEVWSRGT-UHFFFAOYSA-N
SMILES [Cr]=[Se]
Properties
Chemical formula	CrSe
Molar mass	130.96 g/mol
Appearance	white to pale yellow crystalline powder
Density	6.74 g/cm3
Melting point	~1500 °C
Solubility in water	insoluble
Structure[1]
Crystal structure	NiAs type (hexagonal)
Space group	P63/mmc, No. 194
Lattice constant	a = 371 pm, c = 603 pm
Hazards
NFPA 704 (fire diamond)	1 1 1
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 1 mg/m3[2]
REL (Recommended)	TWA 0.5 mg/m3[2]
IDLH (Immediate danger)	250 mg/m3[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references