Modeling exact exchange potential in spherically confined atoms

Area of Science:

• Computational chemistry
• Quantum chemistry
• Atomic physics

Background:

• Accurate electron density is crucial for understanding atomic and molecular properties.
• Local exchange potentials are essential approximations in electronic structure calculations.
• Confinement effects significantly alter atomic electronic structure.

Purpose of the Study:

• To derive local exchange potentials for confined atoms using the Zhao-Morrison-Parr (ZMP) method.
• To compare ZMP-derived potentials and electron densities with the Becke-Johnson (BJ) model.
• To evaluate the performance of other exchange potentials (SCα-LDA, Becke-88) for confined systems.

Main Methods:

• Application of the Zhao-Morrison-Parr method to obtain local exchange potentials.
• Hartree-Fock (HF) electron density as a reference for confined atoms and ions.
• Comparison with Becke-Johnson (BJ) potential, including systematic scaling.
• Assessment of SCα-LDA and Becke-88 exchange potentials.

Main Results:

• The ZMP method successfully generated local exchange potentials for confined systems.
• Scaling the BJ potential significantly improved the accuracy of the resulting electron density.
• An optimal scaling factor for the BJ potential was found to increase with decreasing confinement radius.
• The SCα-LDA and Becke-88 potentials showed varying performance in reproducing HF densities.

Conclusions:

• A scaled BJ potential offers an improved description of electron densities in confined atoms.
• The ZMP method provides a viable route to accurate local exchange potentials for confined systems.
• Confinement effects necessitate adjustments to existing exchange potential models.