Calculating the Lifetimes of Metastable States with Complex Density Functional Theory

Area of Science:

• Quantum Chemistry
• Theoretical Chemistry
• Computational Physics

Background:

• Metastable states are crucial in understanding chemical reactions and molecular properties.
• Complex absorbing potentials (CAPs) are established tools for analyzing these short-lived states.
• Existing methods require extensions to handle the non-Hermitian nature of CAP-modified Hamiltonians.

Purpose of the Study:

• To introduce and validate the application of complex density functional theory (CODFT) to metastable systems.
• To demonstrate the synergy between CAPs and CODFT for accurate theoretical predictions.
• To investigate the resonance properties of specific atomic and molecular systems.

Main Methods:

• Integration of complex absorbing potentials (CAPs) into a complex density functional theory (CODFT) framework.
• Extension of the Kohn-Sham method to non-Hermitian systems using CODFT.
• Application of conventional exchange-correlation functionals to complex densities.

Main Results:

• Successful application of CODFT with CAPs to model metastable systems for the first time.
• Accurate prediction of resonance positions and lifetimes for beryllium negative ions and the nitrogen molecule.
• Results align with established theoretical findings from other studies.

Conclusions:

• CODFT provides a robust theoretical framework for studying metastable states.
• The combination of CAPs and CODFT offers a powerful computational tool for quantum chemistry.
• This methodology opens new avenues for investigating short-lived electronic states.