Development of calculation and analysis methods for the dynamic first hyperpolarizability based on the ab initio...

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Nonlinear Optics

Background:

• Dynamic first hyperpolarizabilities (β) are crucial molecular-level second-order nonlinear optical (NLO) properties.
• Understanding these properties is key for designing advanced optical materials.

Purpose of the Study:

• To develop and validate novel computational methods for calculating dynamic β.
• To analyze electron contributions and establish structure-property relationships for NLO materials.

Main Methods:

• Utilized the quantum master equation method combined with ab initio molecular orbital (MO) configuration interaction.
• Applied these methods to calculate off-resonant dynamic β for substituted benzenes.
• Analyzed dynamic β density and MO contributions to electron spatial distribution.

Main Results:

• The developed methods accurately reproduce dynamic β values compared to the conventional summation-over-states method.
• Successfully evaluated off-resonant dynamic β for donor/acceptor-substituted benzenes.
• Provided insights into electron spatial contributions to dynamic β.

Conclusions:

• The novel methods offer an advantage in unraveling the mechanisms of dynamic NLO properties.
• These methods facilitate the establishment of structure-dynamic NLO property relationships for practical molecular design.