Unfortunately, with my current knowledge, B2O5Se2 is not recognized as a chemical compound. Molecules containing elements B (Boron), O (Oxygen) and Se (Selenium) need to comply with the rules of valency and reasonable molecular structure. The B2O5Se2 molecule with this structure does not comply with these rules.
You may have written the chemical formula incorrectly. Please check again or refer to textbooks, chemical documents or reliable online sources.
If you need more information about other chemical compounds such as H2O (water), NaCl (table salt), CO2 (carbon dioxide),… please let me know, I would be very happy to help.