Shape corrections to exchange-corelation potentials by gradient-regulated seamless connection of model potentials for inner and outer region

摘要

Shape corrections to the standard approximate Kohn-Sham exchange-correlation (xc) potentials are considered with the aim to improve the excitation energies (especially for higher excitations) calculated with time-dependent density functional perturbation theory .A scheme of1 gradient-regulated connection (GRAC;:) of inner to outer parts of a model potential is developed. Asymptotic corrections based either on the potential of Fermi and Amaldi or van Leeuwen and Baerends (LB) are seamlessly connected to the (shifted) xc potential of Becke and Perdew (BP) with theGRAC procedure, and are employed to calculate the vertical excitation energies oftlie prototype molecules N2, CO,CH2O,<;::2H4, C5NH5.C6H6, Li2, Na2, K2. The results are co~pared with those of the alternative interpolation scheme of Tozer and Handy as well as with the results of the potential obtained with the statistical averaging of (model) orbital potentials. Various asymptotically corrected potentials produce high quality excitation energies, which in quite a few cases approach the benchmark accuracy of 0.1 eVtor th~ electronic spectra. Based on these results, the potential BP-GRAC-LB is proposed for molecular response calculations, which is a smooth potential and a genuine "local" density functional with an analytical representation.