Atomic Charge Calculation of Metallobiomolecules in Terms of the ABEEM Method.

Abstract

Applying the atom-bond electronegativity equalization method (ABEEM) to metallobiomolecules, the ABEEM parameters for transition metals (V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) were calibrated through linear regression and least-squares optimization by choosing more than 300 training molecules. The quality of the ABEEM charge calculated in terms of the optimized electronegativity and hardness parameters for the training set is assessed by comparison with B3LYP/6-31G* charges. For a check, the ABEEM charges of some large metallobiomolecules have been calculated, and the obtained results correlate quite well to those calculated with the B3LYP/6-31G* method. The linear correlation coefficients R are all over 0.98. This shows that the ABEEM method can predict the charge distributions of large metallobiomolecules with high accuracy.