Comparative analysis of the performance of commonly available density functionals in the determination of geometrical parameters for copper complexes

Abstract

In this study, a set of 50 transition-metal complexes of Cu(I) and Cu(II), were used in the evaluation of 18 density functionals in geometry determination. In addition, 14 different basis sets were considered, including four commonly used Pople's all-electron basis sets; four basis sets including popular types of effective-core potentials: Los Alamos, Steven-Basch-Krauss, and Stuttgart-Dresden; and six triple-ζ basis sets. The results illustrate the performance of different methodological alternatives for the treatment of geometrical properties in relevant copper complexes, pointing out Double-Hybrid (DH) and Long-range Correction (LC) Generalized Gradient Approximation (GGA) methods as better descriptors of the geometry of the evaluated systems. These however, are associated with a computational cost several times higher than some of the other methods employed, such as the M06 functional, which has also demonstrated a comparable performance. Regarding the basis sets, 6-31+G(d) and 6-31+G(d,p) were the best performing approaches. In addition, the results show that the use of effective-core potentials has a limited impact, in terms of the accuracy in the determination of metal-ligand bond-lengths and angles in our dataset of copper complexes. Hence, these could become a good alternative for the geometrical description of these systems, particularly CEP-121G and SDD basis sets, if one is considering larger copper complexes where the computational cost could be an issue.

Benchmarking of density functionals for the kinetics and thermodynamics of the hydrolysis of glycosidic bonds catalyzed by glycosidases

“…The widely used functional B3LYP, is also among the most accurate functionals, with a MUE of 0.04 Å and angle deviation lower than 1.1 degrees, showing, in fact, a better performance than in other benchmarking studies …”

Geometrical and optical benchmarking of copper(II) guanidine–quinoline complexes: Insights from TD‐DFT and many‐body perturbation theory (part II)

“…Finally, we conclude that B3LYP seems to serve as a good starting point for the electronic structure calculations of the present charge‐transfer systems which are of considerable size. In the literature, B3LYP is discussed ambiguously: on the one hand, this “workhorse” of quantum chemistry yields astonishingly good energetic and optical predictions with small basis sets and is hence extremely widely used; on the other hand, it suffers from severe shortcomings such as increasing energetic errors with increasing molecular size and sometimes unreliability for transition metal systems . Ramos et al found that B3LYP is an average performing functional for small copper complexes.…”

Application of quantum mechanics/molecular mechanics methods in the study of enzymatic reaction mechanisms

“…Starting from an optimized enzyme‐complex guess, we are in a position to start exploring different hypothesis for our reaction to take place. At this stage, linear transit scans are performed to explore the PES resulting from the guess reaction coordinates, with a polarized double zeta basis set, such as 6‐31G(d), being routinely employed, since structural changes are less sensitive to the choice of basis set . These linear scans can be performed with increments in internal coordinates, typically bond lengths.…”

“…At this stage, linear transit scans are performed to explore the PES resulting from the guess reaction coordinates, with a polarized double zeta basis set, such as 6-31G (d), being routinely employed, since structural changes are less sensitive to the choice of basis set. 109,110,114 These linear scans can be performed with increments in internal coordinates, typically bond lengths. Initially, linear scans with increments in the range of 0.05-0.10 Å and few optimization cycles should be preferred; in this way the PES is explored faster and familiarizes the user with the main changes occurring in the system.…”