An efficient implementation of the localized operator partitioning method for electronic energy transfer

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Molecular Physics

Background:

• The localized operator partitioning method precisely defines electronic energy for molecular subsystems.
• Investigating electronic energy transfer requires accurate subsystem ground and excited electronic energies.
• Previous implementations were computationally hindered by complex integrals.

Purpose of the Study:

• To develop a computationally efficient formulation of the localized operator partitioning method.
• To enable accurate first-principles investigation of electronic energy transfer.
• To analyze subsystem electronic energies and populations in excited states.

Main Methods:

• Reformulated the localized operator partitioning method using a resolution of the identity.
• Developed an algorithm involving standard one- and two-electron integrals.
• Applied the method to the 9-((1-naphthyl)-methyl)-anthracene (A1N) molecule using configuration interaction singles (CIS).

Main Results:

• The reformulated method is computationally efficient.
• Successfully partitioned A1N into anthracenyl and CH2-naphthyl subsystems.
• Examined electronic energies and populations for multiple excited states.
• Observed diverse behaviors among the excited electronic states.

Conclusions:

• The computationally efficient localized operator partitioning method is now feasible.
• This advancement facilitates first-principles studies of electronic energy transfer.
• The analysis of A1N reveals complex excited-state dynamics in molecular subsystems.