On the Choice of a Distributed Basis Set in Calculations of Transition-Dipole Moments in the One-Determinant Approximation

摘要

The so-called "asymptotic projection technique" developed in previous papers of the authors is applied to the calculation of electronic transition-dipole moments (TDMs) in the one-determinant approximation between states of the same spin and spatial symmetry. The basic equations of the method and specific features of their application to a TDM calculation are briefly discussed. The attention focusses on the choice of a finite one-particle basis set. For this purpose, two possible algorithms for constructing distributed basis sets are proposed. In the first of them, the construction is based on minimization of the Hartree-Fock energy (E (HF) ) with respect to nonlinear basis set parameters. In the second case, the parameters are determined by minimizing the functional E = E (HF) + E (MP2), which includes the electron correlation through the second order of Moller-Plesset perturbation theory (D center dot (DeD 2)). On the whole, the results of calculations in both basis sets are in agreement with high-accuracy calculations performed by configuration interaction methods. The basis set adapted for E = E (HF) + E (MP2) significantly improves the accuracy as compared to the basis set of the first type.