Journal article
A new dipole-free sum-over-states expression for the second hyperpolarizability
The Journal of chemical physics, Vol.128(8), pp.084109-084109-11
02/28/2008
Handle:
https://hdl.handle.net/2376/109152
PMID: 18315035
Abstract
The generalized Thomas-Kuhn sum rules are used to eliminate the explicit dependence on dipolar terms in the traditional sum-over-states (SOS) expression for the second hyperpolarizability to derive a new, yet equivalent, SOS expression. This new dipole-free expression may be better suited to study the second hyperpolarizability of nondipolar systems such as quadrupolar, octupolar, and dodecapolar structures. The two expressions lead to the same fundamental limits of the off-resonance second hyperpolarizability; and when applied to a particle in a box and a clipped harmonic oscillator, have the same frequency dependence. We propose that the new dipole-free equation, when used in conjunction with the standard SOS expression, can be used to develop a three-state model of the dispersion of the third-order susceptibility that can be applied to molecules in cases where normally many more states would have been required. Furthermore, a comparison between the two expressions can be used as a convergence test of molecular orbital calculations when applied to the second hyperpolarizability.
Metrics
26 Record Views
Details
- Title
- A new dipole-free sum-over-states expression for the second hyperpolarizability
- Creators
- Javier Pérez-Moreno - Department of Chemistry, University of Leuven, Celestijnenlaan 200D, B-3001 Leuven, BelgiumKoen Clays - Department of Chemistry, University of Leuven, Celestijnenlaan 200D, B-3001 Leuven, BelgiumMark Kuzyk - Department of Chemistry, University of Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium
- Publication Details
- The Journal of chemical physics, Vol.128(8), pp.084109-084109-11
- Academic Unit
- Department of Physics and Astronomy
- Publisher
- American Institute of Physics
- Number of pages
- 11
- Grant note
- ECS-0354736 / NSF
- Identifiers
- 99900547045801842
- Language
- English
- Resource Type
- Journal article