title: Comparative analysis of the performance of commonly available density functionals in the determination of geometrical parameters for zinc complexes.
abstract: A set of 44 Zinc-ligand bond-lengths and of 60 ligand-metal-ligand bond angles from 10 diverse transition-metal complexes, representative of the coordination spheres of typical biological Zn systems, were used to evaluate the performance of a total of 18 commonly available density functionals in geometry determination. Five different basis sets were considered for each density functional, namely two all-electron basis sets (a double-zeta and triple-zeta formulation) and three basis sets including popular types of effective-core potentials: Los Alamos, Steven-Basch-Krauss, and Stuttgart-Dresden. The results show that there are presently several better alternatives to the popular B3LYP density functional for the determination of Zn-ligand bond-lengths and angles. BB1K, MPWB1K, MPW1K, B97-2 and TPSS are suggested as the strongest alternatives for this effect presently available in most computational chemistry software packages. In addition, the results show that the use of effective-core potentials (in particular Stuttgart-Dresden) has a very limited impact, in terms of accuracy, in the determination of metal-ligand bond-lengths and angles in Zinc-complexes, and is a good and safe alternative to the use of an all-electron basis set such as 6-31G(d) or 6-311G(d,p).
authors.affiliation: REQUIMTE, Departamento de Química, Faculdade de Ciõncias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal.
authors.forename: Sérgio F
authors.initials: SF
authors.lastname: Sousa
authors.forename: Emanuela S
authors.initials: ES
authors.lastname: Carvalho
authors.forename: Diana M
authors.initials: DM
authors.lastname: Ferreira
authors.forename: Isabel S
authors.initials: IS
authors.lastname: Tavares
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Fernandes
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Ramos
authors.forename: José A N F
authors.initials: JA
authors.lastname: Gomes
mesh_terms: D003198:Computer Simulation; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry; D011789:Quantum Theory; D012984:Software; D015032:Zinc / Q000737:chemistry*
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D015032:Zinc