Zero-cost corrections to influence functional coefficients from bath response functions.

Area of Science:

• Computational Chemistry
• Quantum Dynamics
• Statistical Mechanics

Background:

• Direct calculation of discretized influence functional coefficients from classical trajectories is possible but limited by high-temperature approximations.
• Existing methods require accurate spectral density calculations, which can be computationally intensive.

Purpose of the Study:

• To develop an alternative derivation for influence functional coefficients using Kubo formalism.
• To introduce correction terms that extend the applicability of the direct calculation method to lower temperatures.
• To enable direct use of correlation functions from advanced molecular dynamics methods.

Main Methods:

• Derivation based on the Kubo formalism.
• Calculation of additional correction terms for influence functional coefficients.
• Investigation of accuracy across various parameters for both original and corrected procedures.

Main Results:

• The Kubo formalism-based approach allows for correction terms that improve accuracy at lower temperatures.
• The method directly incorporates correlation functions from ring-polymer molecular dynamics and centroid molecular dynamics.
• Correction terms are obtained at no additional computational cost and can be further refined.

Conclusions:

• The enhanced method extends the applicability of direct influence functional coefficient calculation to lower temperatures.
• This approach offers a computationally efficient and accurate way to incorporate system-solvent interactions.
• Further improvements are possible with minimal additional effort, enhancing the method's practical utility.