Linear response coupled cluster theory with the polarizable continuum model within the singles approximation for the...

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Coupled cluster (CC) methods are accurate for electronic structure calculations.
• Modeling solvation effects is crucial for understanding molecular properties in solution.
• Accurate calculation of response properties requires efficient theoretical frameworks.

Purpose of the Study:

• To develop and implement a computationally efficient linear response theory for solvated systems using CC methods.
• To approximate the solvent response within the polarizable continuum model (PCM).
• To evaluate the performance of the new perturbation theory with energy and singles density (PTES) scheme.

Main Methods:

• Implementation of the linear response function for CC with single and double excitations (CCSD).
• Approximation of solvent response using the PTES scheme, retaining only CC single excitation amplitudes.
• Comparison of PTES with the full-density (PTED) method.
• Application to calculate excitation energies, transition dipoles, polarizability, and specific rotation of solvated molecules.

Main Results:

• The PTES scheme shows negligible differences compared to the more computationally expensive PTED method.
• PTES provides a significant reduction in computational cost.
• The accuracy of PTES is validated across various response properties for solvated systems.

Conclusions:

• The PTES scheme is a computationally efficient and accurate approach for calculating response properties of solvated systems.
• This method is general and applicable to various solvation models, including explicit solvent representations.
• PTES offers a competitive alternative for quantum chemistry calculations involving solvated molecules.