Genäherte natürliche Orbitale für die Grundzustände von Li und Li-; Elektronenaffinität von Li- / Approximate natural orbitals for the groundstates of li and li-; electron-affinity of li-

Abstract

Abstract Starting from a set of Slater-type atomic orbitals with seven s-, four p-, one d- and one f-type functions the total wavefunction is constructed by a C I-calculation. The highest degree of the secular equation is 84 for Li (2S) and 142 for Li- (1S). By diagonalizing the first-order density matrices approximate natural orbitals are obtained. These are analysed and used again in a further C I-calculation. The best values for the electron-affinity are 0.572 eV and 0.614 eV. For the latter value only the correlaton energy of the L-shell of Li- is considered