Sparkle/PM7 Lanthanide Parameters for the Modeling of Complexes and Materials.

TLDR: The capability of the use of the Sparkle Model for the prediction of geometries of compounds containing lanthanide trications within the PM7 semiempirical model is emphasized, as well as the usefulness of such semiempireical calculations for materials modeling.

Abstract: The recently published Parametric Method number 7, PM7, is the first semiempirical method to be successfully tested by modeling crystal structures and heats of formation of solids. PM7 is thus also capable of producing results of useful accuracy for materials science and constitutes a great improvement over its predecessor, PM6. In this article, we present Sparkle model parameters to be used with PM7 that allow the prediction of geometries of metal complexes and materials which contain lanthanide trications. Accordingly, we considered the geometries of 224 high-quality crystallographic structures of complexes for the parametrization set and 395 more for the validation of the parametrization for the whole lanthanide series, from La(III) to Lu(III). The average unsigned error for Sparkle/PM7 for the distances between the metal ion and its coordinating atoms is 0.063 A for all lanthanides, ranging from a minimum of 0.052 A for Tb(III) to 0.088 A for Ce(III), comparable to the equivalent errors in the distanc...