Multiconfigurational Effects in Theoretical Resonance Raman Spectra.
Chemphyschem
; 18(4): 384-393, 2017 Feb 17.
Article
em En
| MEDLINE
| ID: mdl-27933695
ABSTRACT
We analyze resonance Raman spectra of the nucleobase uracil in the short-time approximation calculated with multiconfigurational methods. We discuss the importance of static electron correlation by means of density-matrix renormalization group self-consistent field (DMRG-SCF) calculations. Our DMRG-SCF results reveal that a minimal active orbital space that leads to a qualitatively correct description of the resonance Raman spectrum of uracil should encompass parts of the σ/σ* bonding/anti-bonding orbitals of the pyrimidine ring. We trace these findings back to the considerable entanglement between the σ/σ* bonding/anti-bonding as well as valence π/π* orbitals in the excited-state electronic structure of uracil, which indicates non-negligible non-dynamical correlation effects that are less pronounced in the electronic ground state.
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Base de dados:
MEDLINE
Assunto principal:
Teoria Quântica
/
Análise Espectral Raman
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Uracila
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article