An extremely efficient algorithm for (2,2) dynamically weighted constrained complete active space calculations

Area of Science:

• Computational chemistry
• Surface science
• Electrochemistry

Background:

• Electron transfer at metal surfaces is crucial for many electrochemical processes.
• Accurate computational modeling of these processes is computationally intensive and challenging.
• Existing methods often require significant computational resources, limiting their application.

Purpose of the Study:

• To develop an efficient and accurate computational algorithm for modeling electron transfer at metal surfaces.
• To generate balanced ground and excited state energy surfaces for charge-transfer processes.
• To reduce the computational cost of simulating heterogeneous electron transfer.

Main Methods:

• Implementation of a dynamically weighted, state-averaged, constrained complete active space self-consistent field [DW-SA-cCASSCF(2,2)] calculation.
• The algorithm is designed to be computationally inexpensive, comparable to mean-field methods like Hartree-Fock.
• Focus on generating accurate energy surfaces for charge-transfer dynamics.

Main Results:

• The DW-SA-cCASSCF(2,2) algorithm significantly reduces computational effort compared to previous methods.
• The method achieves a computational cost comparable to mean-field calculations.
• It successfully generates balanced ground and excited state energy surfaces relevant to charge transfer.

Conclusions:

• The developed DW-SA-cCASSCF(2,2) algorithm offers an efficient approach to model electron transfer at metal surfaces.
• The reduced computational cost makes it feasible for studying nonadiabatic dynamics.
• This method promises to provide valuable computational insights into heterogeneous electron transfer processes.