Frank E. Harris
Department of Physics, University of Utah
Quantum Theory Project, University of Florida
Int. J. Quantum Chem. 63, 913-916 (1997)
The leaky aquifer function W(x,y), an incomplete Bessel function which has had application in hydrology, is now also arising in electronic-structure calculations on periodic systems. This work presents an expansion which improves the efficiency of calculation of W in the range where x and y are comparable and both are larger than unity.