Unfortunately, Se5F5 is not the name of a chemical substance that is currently identified or known. You might have misspelled the name of the chemical you wish to investigate.
Please note that each chemical substance has a unique name and specific molecular structure, and it is not possible to arbitrarily change or adjust the number of atoms or type of elements in their molecules.
For instance, SeF6 is the name of a well-known chemical – Selenium hexafluoride – which consists of one Selenium atom and six Fluorine atoms. You might want to revise the information you have to ensure you are searching for the correct chemical.
If you have a specific chemical substance you wish to investigate, please provide its exact name so we can provide the most detailed and accurate information.