. Author manuscript; available in PMC: 2021 Jan 14.

Published in final edited form as: J Chem Theory Comput. 2019 Dec 26;16(1):587–600. doi: 10.1021/acs.jctc.9b00823

Table 2:

Excitation energies (in eV) for DFT-optimized protein models of the green fluorescent protein (GFP) and the retinoid-binding protein II (hCRBPII) calculated at the CC2 and TDDFT levels using a few selected functionals. The calculations were performed with def2-TZVP basis sets.

Model/Method	CC2	B3LYP	CAM-B3LYP	CAMh-B3LYP	Exp.
GFP-A^a	3.13	2.98	3.70	3.14	3.12
GFP-B^a	2.72	2.91	2.79	2.76	2.61
hCRBPII-S2^b	2.37	1.78	2.60	2.51	2.44
hCRBPII-S3^b	2.13	1.45	2.42	2.39	2.10
hCRBPII-S6^b	2.03	1.26	2.34	2.31	1.99

CC2 data and protein model from Refs 10 and 11.

CC2 data and protein model from Ref. 109.