ausblenden:
Schlagwörter:
electronic-structure theory,
basis sets,
explicit-correlation methods,
randomphase approximation,
numeric atom-centered orbital,
valence-correlation consistency,
counterpoise correction,
density-functional theory,
second order Møller-Plesset perturbation theory
Zusammenfassung:
We present a series of numerically tabulated atom-centered orbital (NAO) basis sets
with valence-correlation consistency (VCC), termed NAO-VCC-nZ. Here the index
\nZ" refers to the number of basis functions used for the valence shell with n = 2, 3,
4, 5. These basis sets are constructed analogous to Dunning's cc-pVnZ, but utilize
the more
exible shape of NAOs. Moreover, an additional group of (sp) basis functions,
called enhanced minimal basis, is established in NAO-VCC-nZ, increasing the
contribution of the s and p functions to achieve the valence-correlation consistency.
NAO-VCC-nZ basis sets are generated by minimizing the frozen-core RPA total energies
of individual atoms from H to Ar. We demonstrate that NAO-VCC-nZ basis
sets are suitable for converging electronic total-energy calculations based on valenceonly
(frozen-core) correlation methods which contain explicit sums over unoccupied
states (e.g., the random-phase approximation (RPA) or second order Mller-Plesset
perturbation theory (MP2)). The basis set incompleteness error, including the basis
set superposition error, can be gradually reduced with the increase of the index \n",
and can be removed using two-point extrapolation schemes.
