I did a post of favorite study hideouts last semester and this semester, I have a bunch more:
The library is probably not your best bet to get work done quietly and alone (I have barely ever studied in the library).
1. JILA Tower.
2. Department Labs (For me, I have access to the KESDAL lab at the GEOG building. You should have access to special rooms and labs in your department building after hours).
3. UMC 5th Floor.
4. Off-campus local Coffee Shops.
5. BOLD Center, Engineering.