Continuum remover-complex absorbing potential: Efficient removal of the nonphysical stabilization points.

Area of Science:

• Quantum mechanics
• Computational chemistry
• Atomic physics

Background:

• Resonance states in quantum systems are crucial for understanding scattering and reaction dynamics.
• Complex energy stabilization points in Hamiltonian trajectories are used to locate these resonance states.
• Distinguishing physical from nonphysical complex energy points presents a significant challenge in computational methods.

Purpose of the Study:

• To develop a novel method for reliably identifying physical complex energy stabilized points.
• To provide a robust approach for separating physically meaningful resonance states from artifacts in calculations.
• To demonstrate the efficacy of the proposed method, particularly for strongly correlated two-electron systems.

Main Methods:

• Introduction of a negative imaginary potential of variable strength (eta) into the system's Hamiltonian.
• Analysis of the trajectories of complex eigenvalues as a function of the imaginary potential strength.
• Development of criteria to differentiate between physical and nonphysical complex energy stabilized points.

Main Results:

• A clear distinction is established between physical and nonphysical complex energy stabilization points.
• The proposed method effectively isolates the true resonance states of the system.
• The method's applicability is demonstrated using challenging strongly correlated two-electron systems.

Conclusions:

• The new method offers a reliable way to identify physical resonance states in quantum systems.
• This approach overcomes a key limitation in current computational techniques for resonance calculations.
• The findings are particularly relevant for accurate theoretical studies of complex atomic and molecular systems.