## quantized internal energy

https://doi.org/10.1351/goldbook.Q04979
The quantized @[email protected] of a molecule in its electronic ground or @[email protected] can be approximated with sufficient accuracy for analytical purposes by: $E_{\text{int}}=E_{\text{el}}+E_{\text{vib}}+E_{\text{rot}}$ where $$E_{\mathrm{el}}$$ is the electronic, $$E_{\mathrm{vib}}$$ the vibrational and $$E_{\mathrm{rot}}$$ the rotational energy, respectively.
Source:
PAC, 1988, 60, 1449. (Nomenclature, symbols, units and their usage in spectrochemical analysis - VII. Molecular absorption spectroscopy, ultraviolet and visible (UV/VIS) (Recommendations 1988)) on page 1452 [Terms] [Paper]