Where does “диарсенид” come from?

диарсенид (Russian) comes from Russian арсени́д, from German Arsenid — arsenide.

Ancestry of “диарсенид”, step by step

StepLanguageWordMeaning
1Russianарсени́дarsenide
2GermanArsenidarsenide
Every word from German ArsenidEvery word from Russian арсени́д