# What is the largest known zero-point energy for a molecule?

I was surprised to find out that the zero-point energy (ZPE) for the ground state of $$\ce{BH3}$$ is a few thousand $$\pu{cm-1}$$, because for molecules I usually work with, it's much smaller. Does anyone know the largest recorded ZPE?

I have recently asked a similar question: What is the biggest known difference between $$r_e$$ and $$r_0$$?

• Liquid helium, maybe? Aug 30 '19 at 22:56
• @OscarLanzi: Why liquid helium? Aug 30 '19 at 23:19
• My understanding is this is what keeps it liquid to absolute zero unless compressed. Aug 30 '19 at 23:37
• Is the question about vibrational zpe? see eg nist.gov/sites/default/files/documents/srd/jpcrd362007389p.pdf Aug 31 '19 at 7:45
• @buck of interest in your reference: Mg2 (which may form a weak bond if s-p mixing occurs in its MOs), NaLi (which may be considered a lithide). Aug 31 '19 at 12:10