Multistate Multiconfiguration Quantum Chemical Computation of the Two-Photon Absorption Spectra of Bovine Rhodopsin.

ABSTRACT: Recently, progress in IR sources has led to the discovery that humans can detect infrared (IR) light. This is hypothesized to be due to the two-photon absorption (TPA) events promoting the retina dim-light rod photoreceptor rhodopsin to the same excited state populated via one-photon absorption (OPA). Here, we combine quantum mechanics/molecular mechanics and extended multiconfiguration quasi-degenerate perturbation theory calculations to simulate the TPA spectrum of bovine rhodopsin (Rh) as a model for the human photoreceptor. The results show that the TPA spectrum of Rh has an intense S₀ → S₁ band but shows also S₀ → S₂ and S₀ → S₃ transitions whose intensities, relative to the S₀ → S₁ band, are signi

SUBMITTER: Gholami S 

PROVIDER: S-EPMC7141604 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature