Published In
Axioms
Document Type
Article
Publication Date
4-27-2026
Subjects
Green function; hydrogenic wave functions; Hylleraas wave functions; ellipsoidal coordinates; Hylleraas coordinates, Indefinite integrals of Macdonald functions; modified spherical Bessel function of the second kind, Reduced Bessel functions
Abstract
Addition theorems have been indispensable tools for the reduction of quantum transition amplitudes. They are normally utilized at the start of the process to move the angular dependence within plane waves, Coulomb potentials, and the like, into a sum over spherical harmonics that allows the angular integration to be carried out. These have historically been “two-range” addition theorems, characterized by the two-fold notation r>=Max[r1,r2] and r< =Min[r1,r2] and comprising a single infinite series. More recently, “one-range” addition theorems have been created that have no such piecewise notation, but at the cost of the introduction of another infinite series. We use a very different approach to derive an infinite set of addition theorems for Slater orbitals, hydrogenic and Hylleraas wave functions, and so on, that retain the one-range variable dependence but have, at worst, a finite second series rather than an infinite one. In addition, unlike previous addition theorems, they are applicable to more than one coordinate system. One of these addition theorems may also be used for Yukawa-like functions that may appear late in the reduction of amplitude integrals, and we show its utility for an integral that has stubbornly defied reduction to analytic form for nearly sixty years. Finally, we craft indefinite integrals of 15 half-integer Macdonald functions multiplied by (inverse) powers and negative exponentials containing squares of the integration variable.
Rights
Copyright (c) 2026 The Authors
This work is licensed under a Creative Commons Attribution 4.0 International License.
DOI
10.3390/axioms15040242
Persistent Identifier
https://archives.pdx.edu/ds/psu/44651
Citation Details
Straton, J. C. (2026). An Infinite Set of One-Range Addition Theorems Without an Infinite Second Series, for Slater Orbitals and Their Derivatives, Applicable to Multiple Coordinate Systems. Axioms, 15(4), 242.