Calcium disilicide

Calcium disilicide
	hR9 unit cell
Identifiers
CAS Number	12013-56-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	3365368;
ECHA InfoCard	100.031.431
EC Number	234-588-7;
PubChem CID	170839545;
CompTox Dashboard (EPA)	DTXSID70892171 ;
	InChI InChI=1S/Ca.2Si Key: HAUJAPUPPYHUGS-UHFFFAOYSA-N;
	SMILES [Si].[Si].[Ca];
Properties
Chemical formula	CaSi2
Molar mass	96.249 g/mol
Appearance	grey solid
Density	2.50 g/cm3
Melting point	1,040 °C (1,900 °F; 1,310 K)
Solubility in water	insoluble
Structure
Crystal structure	Trigonal, hR9/hR18,
Space group	R3m, No. 166
Lattice constant	a = 0.38295/0.3855 nm, c = 1.5904/3.06 nm
Formula units (Z)	3/6
Hazards
	GHS labelling:[1]
Pictograms
Signal word	Danger
Hazard statements	H261
Precautionary statements	P231+P232, P280, P370+P378, P402+P404, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Calcium disilicide (Ca Si₂) is an inorganic compound, a silicide of calcium. It is a whitish or dark grey to black solid matter with melting point 1033 °C. It is insoluble in water, but may decompose when subjected to moisture, evolving hydrogen and producing calcium hydroxide. It decomposes in hot water, and is flammable and may ignite spontaneously in air.

Industrial calcium silicide usually contains iron and aluminium as the primary contaminants, and low amounts of carbon and sulfur.