Speaker
Ryan Peck
Description
Quantum defects are useful in interpreting high energy atomic states in terms of
simple Hydrogenic energy levels. We will find the energy levels
for 1snp singlet and triplet P state Helium from $n = 2$ to $n = 12$ with some of the most
accurate helium atom calculations to date using the exact non-relativistic Hamiltonian with wave functions expanded in a basis set of Hylleraas coordinates. The results will be used to determine accurate values for the coefficients in the quantum defect expansion: $\delta = \delta_0 + \delta_2/n^{*2} + \delta_4/n^{*4} + \cdots$, where $n^* = n - \delta$. We will also test the usual assumption that only the even powers of $1/n^*$ need be included [1]. In addition, we will study the effectiveness of a unitary transformation in reducing the numerical linear dependence of the basis set for large basis sets.
Author
Gordon Drake
(University of Windsor)
Co-authors
Ryan Peck
Mr
Travis Valdez
(Drake Research Group)
