Optimized effective potentials from arbitrary basis sets.

Area of Science:

• Quantum Chemistry
• Computational Physics
• Materials Science

Background:

• Optimized Effective Potential (OEP) methods are crucial for accurate electronic structure calculations.
• Determining physically meaningful OEPs from finite basis sets presents numerical stability challenges.
• Existing regularization techniques require careful parameter selection.

Purpose of the Study:

• To develop a robust regularized OEP energy functional and L-curve procedure for generating accurate OEPs.
• To rigorously determine the optimal regularization parameter using the Ghosh-Parr exchange energy virial relation.
• To assess the computational stability and accuracy of the proposed method with arbitrary basis sets.

Main Methods:

• Utilized a regularized optimized effective potential (OEP) energy functional.
• Employed an L-curve procedure for regularization parameter determination.
• Introduced the Ghosh-Parr exchange energy virial relation as a measure of potential quality.

Main Results:

• The L-curve approach with the virial relation yields potentials comparable to previous methods.
• This method results in slightly lower exact-exchange total energies.
• Ground-state and orbital energies show good agreement with experimental ionization potentials and other OEP calculations.

Conclusions:

• The regularized OEP functional approach offers a computationally robust solution for OEP calculations.
• This method effectively addresses numerical stability issues in OEP determinations.
• The approach provides accurate potentials and energies, even with unbalanced basis sets.