Overset-Grid Method with Smooth Orbital Partitioning for Molecular Scattering Calculations

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Atomic and Molecular Physics

Background:

• Solving molecular photoionization and electron scattering requires accurate representation of electronic continuum functions.
• Previous overset-grid methods faced limitations in computational efficiency.

Purpose of the Study:

• To present an improved algorithm for molecular photoionization and electron scattering using an overset-grid representation.
• To enhance the efficiency and convergence of computational methods for these problems.

Main Methods:

• Utilized an overset-grid representation with an extended central spherical grid overlapping atomic subgrids.
• Developed a smooth partitioning algorithm for the total wave function between grids.
• Implemented the complex Kohn variational principle for scattering and photoionization amplitudes.

Main Results:

• Achieved a fourfold reduction in partial waves on the central grid compared to previous methods.
• Demonstrated faster convergence with respect to the number of central grid partial waves.
• Verified accuracy through comparisons with previous implementations and computationally intensive methods.

Conclusions:

• The improved algorithm combines the accuracy of grid methods with the rapid convergence of hybrid approaches.
• This method offers a more efficient and flexible approach for electron-molecule scattering and photoionization calculations.
• Successfully applied to systems like Ne2, CF4, and pyridine.