Ab initio lifetime correction to scattering states for time-dependent electronic-structure calculations with...

Area of Science:

• Quantum Chemistry
• Atomic and Molecular Physics
• Computational Chemistry

Background:

• Incomplete basis sets in electronic structure calculations can artificially confine wave functions.
• Accurate lifetimes of scattering electronic states are crucial for understanding atomic and molecular processes.
• Existing methods may rely on empirical parameters or approximations.

Purpose of the Study:

• To develop a method for obtaining effective lifetimes of scattering electronic states.
• To avoid artificial wave function confinement caused by incomplete basis sets.
• To provide an ab initio approach for lifetime calculations.

Main Methods:

• Extracting lifetimes from the spatial asymptotic decay of scattering wave functions.
• Utilizing a fitting procedure on wave functions obtained with a specific basis set.
• Analyzing complex-energy solutions of the Schrödinger equation.

Main Results:

• The proposed method yields lifetimes adapted to any given basis set.
• No empirical parameters are required, making it an ab initio approach.
• Validation on H and He atoms demonstrated the method's effectiveness for high-harmonic-generation spectra.

Conclusions:

• The method effectively determines scattering state lifetimes, overcoming basis set limitations.
• It offers a rigorous and parameter-free alternative to heuristic models.
• This approach enhances the accuracy of time-dependent electronic-structure calculations.