Sparkle model for the quantum chemical AM1 calculation of europium complexes

• Published in: Chemical physics letters 1994-09, Vol.227 (3), p.349-353
• Main Authors: de Andrade, Antônio V.M., da Costa, Nivan B., Simas, Alfredo M., de Sá, Gilberto F.
• Format: Article
• Language: English
• Subjects: Atomic and molecular physics; Calculations and mathematical techniques in atomic and molecular physics (excluding electron correlation calculations); Electronic structure of atoms, molecules and their ions: theory; Exact sciences and technology; Physics; Statistical model calculations (including Thomas-Fermi and Thomas-Fermi-Dirac models)
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/0009-2614(94)00829-9

Considering that the bonds between a lanthanide and its ligands essentially possess an electrostatic character, we propose the representation of rare-earth elements within AM1 as sparkles. To parametrize the sparkle model we have used the known geometry of the complex tris (acetylacetonate) (1,10-phenantroline) of europium (III). Interatomic distances for the coordination polyhedron, averaging 2.81 Å, could be predicted with an average deviation of 0.13 Å. In short, this is a simple lanthanide-ligand electrostatic model which simultaneously treats the organic ligands and their interactions with the powerful AM1 method, yielding results of useful accuracy.