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Noninteger principal quantum numbers increase the efficiency of Slater‐type basis sets
Author(s) -
Koga Toshikatsu,
Kanayama Katsutoshi,
Thakkar Ajit J.
Publication year - 1997
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/(sici)1097-461x(1997)62:1<1::aid-qua1>3.0.co;2-#
Subject(s) - basis (linear algebra) , type (biology) , principal (computer security) , principal quantum number , quantum , basis set , mathematics , physics , computer science , quantum mechanics , density functional theory , geometry , biology , ecology , quantum dissipation , operating system
Roothaan‐Hartree‐Fock (RHF) calculations are carried out for the ground states of the atoms from helium to xenon using a minimal basis set of Slater‐type functions whose principal quantum numbers are allowed to take variationally optimal noninteger values. The resulting energies are substantially superior to those obtained previously under the usual restriction that principal quantum numbers be positive integers. The energy lowering relative to the single‐zeta wave functions of Clementi and co‐workers ranges from 0.0066 E h in He to 11.2 E h in Xe. Our results are superior to those obtained by Höjer using a minimal basis set of unconventional binomially screened basis functions. Noninteger principal quantum numbers benefit d ‐orbitals the most; physically realistic negative d ‐orbital energies are obtained in all cases including those transition‐metal atoms for which a conventional single‐zeta STF basis leads to positive d ‐orbital energies. © 1997 John Wiley & Sons, Inc.