Author ORCID Identifier
https://orcid.org/0000-0001-5116-1515
Document Type
Article
Publication Date
2023
Abstract
We report an improved variational upper bound for the ground state energy of H- using Hylleraaslike wave functions in the form of a triple basis set having three distinct distance scales. The extended precision DQFUN of Bailey, allowing for 70 decimal digit arithmetic, is implemented to retain sufficient precision. Our result exceeds the previous record [A. M. Frolov, Euro. J. Phys. D 69, 132 (2015)], indicating that the Hylleraas triple basis set exhibits comparable convergence to the widely used pseudorandom all-exponential basis sets, but the numerical stability against roundoff error is much better. It is argued that the three distance scales have a clear physical interpretation. The new variational bound is -0.527 751 016 544 377 196 590 814 469 a.u.
Recommended Citation
Drake, Gordon W. F.; Perimoulx, Evan M.R.; Ene, Eric E.A.; Bondy, Aaron T.; and Sati, Lamies A.. (2023). Ground-state energy of H-: a critical test of triple basis sets.
https://scholar.uwindsor.ca/physicspub/198