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

Excitation energies may be improved by making shape corrections to the standard approximate Kohn-Sham exchange-correlation potentials. Asymptotic corrections based on the potential of Fermi and Amaldi are seamlessly connected to the exchange-correlation potential of Becke and Perdew. The results are compared with those of the alternative interpolation scheme of Tozer and Handy. Many asymptotically corrected potentials produce high quality excitation energies. A potential gradient-regulated connection scheme is proposed for molecular response calculations.