Local density component of the Leendash;Yangndash;Parr correlation energy functional

摘要

A systematic study of the local density component (LDC) of the Leendash;Yangndash;Parr (LYP) correlation energy functional on several chemical systems is presented. A total of 22 equilibrium geometries, 28 reaction energies, and 22 atomization energies were calculated using the local density component of the Leendash;Yangndash;Parr correlation energy functional (LDChyphen;LYP). The LDChyphen;LYP results were compared with the correlation energy functional of Vosko, Wilk, and Nusair (VWN), that was parametrized using the exact results of the uniform electron gas approximation. The calculations were performed with local density approximation (LDA) optimized Gaussian basis sets of the doublehyphen;zetahyphen;type plus polarization functions (DZVP2) and the A2 auxiliary basis sets for the density fitting. Comparison with experimental results indicates the geometries and energetics predicted with the LDChyphen;LYP component are in reasonable agreement with those predicted with the VWN approximation for the systems considered. Furthermore, the LDChyphen;LYP+BLYP perturbative approximation is in very good agreement, usually within 2 kcal/mol or less, when compared to the Bhyphen;LYP selfhyphen;consistenthyphen;field (SCF) approach. thinsp;