Expansion calculations with the dirac Hamiltonian: 1S12 and 2P12 states of hydrogenic systems

✍ Scribed by Yasuyuki Ishikawa; Reinaldo Baretty; Kenneth M. Sando

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 599 KB
• Volume: 117
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(85)80280-3

✦ Synopsis

The method or expansion in a balanced basis has bm used for the lS,/, slate of Dirac-Coulomb hydrogenic sys~m using Slaler-type basis functions wfh mteger and non-intep,eer powers of r. A single function with integer power of r is shown lo give the exact lS,/, energy although the wavefunction is not exact. Application of the balanced basis scheme LO the 2P,/, state dm not always lead to an upper bound to the energy unless both upper and lower components of the exact 2P,,2 wavefunction have inlimte cusps al the ong~n Application of the balanced basis expansion of the Drake-Goldman lype to ZP,, fails lo reproduce the nodal structure although the expansion gives tie exact 2P,/1 energy at a single minimum. We discuss how LO avoid such spurious solutions.