The systematic name of Arsenicselenide is diselenoxodiarsaselenane. With the CAS registry number 1303-36-2, it is also named as Diarsenic triselenide. It is black crystals or dark black solid which is insoluble in water and soluble in nitric acid. And the other registry number is 113228-99-2. In addition, it is flammable and will produce toxic selenium and arsenic oxide fumes when buring. The storage environment should be ventilate, low-temperature and dry. Furthermore, Arsenicselenide is used as a chalcogenide glass for infrared optics, as it transmits light with wavelengths between 870 nm and 17.2 µm.

The other characteristics of this product can be summarized as: (1)#H bond acceptors: 0; (2)#H bond donors: 0; (3)#Freely Rotating Bonds: 2; (4)Exact Mass: 387.593546; (5)MonoIsotopic Mass: 389.592758; (6)Heavy Atom Count: 5; (7)Complexity: 34.2; (8)Covalently-Bonded Unit Count: 1.

Preparation of Arsenicselenide: 1. In the 3mm diameter quartz ampoule, adding 25% HCl and the stoichiometric ratio As and Se to the 70% of the volum. Be sealed and placed in the autoclave, adding distilled water to the reactor volume of 72% to ensure that the internally generated enough pressure at the reaction temperature. Then tightening the tank cap and sealed, placed in vertical tube furnace to heat to 365 °C for 3 days, then cooling gradually at about the speed of 2 °C / h within 7 days. Needle-like crystals are growed in the upper part of ampoule. Autoclave pressure is 720bar (calculated by spatial factors 0.70 and the temperature 365 °C, 1bar = 105Pa).
2. The stoichiometric ratio As and Se are sealed in quartz ampoule. And heating 4h at 600 °C in vacuum, then quenched. Glassy material is annealing at 320 °C in 24h. Then the temperature falls to 280 °C at the rate of 5 °C per day. Finally, we can get the As₂Se₃.

When you are using this chemical, please be cautious about it as the following:
It is toxic by inhalation and if swallowed and very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. When using, do not eat or drink. After contact with skin, wash immediately with plenty of soap-suds. In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) This material and its container must be disposed of as hazardous waste. People should avoid release to the environment. Refer to special instructions / safety data sheets.

People can use the following data to convert to the molecule structure.
1. SMILES: [Se]=[As][Se][As]=[Se];
2. InChI: InChI=1/As2Se3/c3-1-5-2-4;
3. InChIKey: WBFMCDAQUDITAS-UHFFFAOYAQ.

The following is the toxicity data which has been tested.