ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The minimal number of independent nonzero atomic integrals that occur over arbitrarily oriented basis orbitals of the form R(r) · Ylm(Ω) is theoretically derived. The corresponding method can be easily applied to any point group, including the molecular continuous groups C∞v and D∞h. On the basis of this (theoretical) lower bound, the efficiency of the permutational approach in generating sets of independent integrals is discussed. It is proved that lobe orbitals are always more efficient than the familiar Cartesian Gaussians, in the sense that GLOs provide the shortest integral lists. Moreover, it appears that the new axial GLOs often lead to a number of integrals, which is the theoretical lower bound previously defined. With AGLOs, the numbers of two-electron integrals to be computed, stored, and processed are divided by factors 2.9 (NH3), 4.2 (C5H5), and 3.6 (C6H6) with reference to the corresponding CGTOs calculations. Remembering that in the permutational approach, atomic integrals are directly computed without any four-indice transformation, it appears that its utilization in connection with AGLOs provides one of the most powerful tools for treating symmetrical species.
Additional Material:
3 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560150107
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