1. Natural perturbation orbital analyses of polarizability and Raman intensity of p-Benzoquinodimethane.
- Author
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Yamaguchi, Keigo and Yamakita, Yoshihiro
- Subjects
- *
NATURAL orbitals , *SINGULAR value decomposition , *MOLECULAR polarizability , *MOLECULAR vibration , *EXCITED states , *ELECTRIC fields , *HILBERT-Huang transform - Abstract
[Display omitted] • Polarizability and Raman intensity of the simplest quinoid hydrocarbon BQM. • SVD analyses for orbital deformations by the electric field and molecular vibrations. • NPOs give an unique orbital representation for electronic deformations in the field. • Large long-axis polarizability and Raman intensity due to HOMO-LUMO promotion. • Mechanism of the weak Raman intensity of the breathing-like CCC stretch mode. The polarizability and Raman intensity of the smallest quinoid hydrocarbon p -benzoquinodimethane were analyzed as electronic deformations in the electric field. The perturbed canonical MOs (CMOs) were transformed to NPOs using the singular value decomposition. The NPOs can represent the intrinsic characters of the electronic deformations that CMOs cannot describe properly. The electronic deformations of HOMO-LUMO type dominate the long-axis polarizability and the strongest Raman intensities. TDDFT calculations demonstrated the relevance of the NPOs to the singly-excited wavefunctions of excited states. The mode-specific predictivity of Raman intensity was discussed based on the polarizability components obtained by B3LYP and CCSD(T) calculations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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