Authors: Javier CarmonaEspíndola José L Gázquez Alberto Vela S B Trickey
Publish Date: 2016/04/13
Volume: 135, Issue: 5, Pages: 120-
Abstract
A nonempirical global hybrid exchange–correlation energy functional which leads to an exchange potential with correct asymptotic behavior is presented The exchange functional combines onefourth of exact exchange with threefourths of the correct asymptotic potential CAP generalized gradient approximation functional It is combined with the Perdew–Burke–Ernzerhof correlation energy with a slightly modified parameterization so as to cancel the gradient terms of CAP exchange with that of correlation in the limit of slowly varying density The resulting global hybrid functional called CAP0 gives heats of formation ionization potentials electron affinities proton affinities binding energies of weakly interacting systems barrier heights for hydrogen and nonhydrogen transfer reactions bond distances and harmonic frequencies on standard test sets that are competitive with results from other longrangecorrected Coulombattenuated or global hybrid functionals In fact they are generally superior to or competitive with CAMPBE0 and except for heats of formation with CAMB3LYP as well Advantageously the Rydberg excitation energies from CAP0 are superior to those of other global hybrids and of the longrangecorrected hybrids They are similar to those from CAMB3LYP and modestly inferior to the CAMPBE0 errors For the valence excitations we did not find substantial differences for all the hybrid functionals considered while the oscillator strengths from CAP0 are better to those of other global hybrids and comparable to those obtained with longrangecorrected and Coulombattenuated hybridsWe thank the Laboratorio de Supercómputo y Visualización of Universidad Autónoma MetropolitanaIztapalapa for the use of their facilities JCE was supported in part by Conacyt and by Universidad Autónoma Metropolitana through postdoctoral fellowships JLG thanks Conacyt for Grant 155698 and AV thanks Conacyt for Grant 128369 SBT was supported in part by US NSF Grant DMR1515307
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