Barium borate

Barium borate
Names
	Other names barium diborate, barium boron oxide, barium metaborate
Identifiers
CAS Number	13701-59-2 ; 19004-06-9 (monohydrate) ; 38720-52-4 (dihydrate) ;
3D model (JSmol)	Interactive image;
ChemSpider	3642855 ;
ECHA InfoCard	100.033.824
EC Number	237-222-4;
PubChem CID	6101043; 23165673 (monohydrate);
UNII	5SE5SRJ05N;
CompTox Dashboard (EPA)	DTXSID1034347 ;
	InChI InChI=1S/2BO2.Ba/c22-1-3;/q2-1;+2 Key: QBLDFAIABQKINO-UHFFFAOYSA-N ; InChI=1/2BO2.Ba/c22-1-3;/q2-1;+2 Key: QBLDFAIABQKINO-UHFFFAOYAX;
	SMILES [Ba+2].[O-]B=O.[O-]B=O;
Properties
Chemical formula	BaB2O4 or Ba(BO2)2
Molar mass	222.95
Appearance	white powder or colorless crystals
Odor	odorless
Density	3.85 g/cm3
Melting point	1,095 °C (2,003 °F; 1,368 K)
Solubility in hydrochloric acid	soluble
Refractive index (nD)	ne = 1.5534, no = 1.6776
Structure
Crystal structure	Rhombohedral, hR126
Space group	R3c, No. 161
Lattice constant	a = 1.2529 nm, c = 1.274 nm
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302
Precautionary statements	P264, P270, P301+P312, P330, P501
Flash point	Non-flammable
Safety data sheet (SDS)	MSDS
	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

Barium borate is an inorganic compound, a borate of barium with a chemical formula BaB₂O₄ or Ba(BO₂)₂. It is available as a hydrate or dehydrated form, as white powder or colorless crystals. The crystals exist in the high-temperature α phase and low-temperature β phase, abbreviated as BBO; both phases are birefringent, and BBO is a common nonlinear optical material.

Barium borate was discovered and developed by Chen Chuangtian and others of the Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences.