Full-potential multiple scattering theory with space-filling cells for bound and continuum states

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Chemistry

Background:

• Existing multiple scattering theory (MST) methods often require complex expansions and approximations.
• Limitations in real-space FP-MST hindered its application in electronic structure calculations and spectroscopy.
• The muffin-tin (MT) approximation simplifies calculations but sacrifices accuracy for non-spherical potentials.

Purpose of the Study:

• To derive a rigorous real-space full-potential multiple scattering theory (FP-MST) free from prior limitations.
• To develop a new scheme for generating local basis functions for efficient calculations.
• To enable accurate computation of electronic structure and X-ray spectroscopies.

Main Methods:

• Developed a real-space FP-MST formulation without spherical harmonics expansion of cell functions.
• Introduced a novel, efficient scheme for generating local basis functions applicable to any cell shape.
• Ensured absolute convergence in the scattering path operator for the l(max) -> ∞ limit.

Main Results:

• The new FP-MST method is valid for both continuum and bound states with less restrictive partitioning.
• It significantly reduces the number of spherical harmonics and avoids internal sum re-expansions.
• The method extends MST to full-potential accuracy with a single truncation parameter, l(max) = kR(b).

Conclusions:

• The presented FP-MST provides a robust and versatile tool for electronic structure calculations.
• It facilitates accurate computation of various X-ray spectroscopies (photo-electron diffraction, absorption, anomalous scattering).
• This work establishes FP-MST as a viable alternative to MT-approximated theories.