Hartree-Fock study on the lower excited states of a Cu+ impurity in NaF using large embedded clusters

We report spin-restricted and symmetry-restricted Hartree-Fock cluster calculations on the lower excited states of a Cu+ impurity in NaF in order to investigate their dependence on cluster size. In contrast to previous work on smaller clusters, we found all states arising from the configurations eg4t2g5a1g1, and eg3t2g6a1g1 to be local. Delocalization can occur when an unbalanced choice of cluster and set of embedding point charges is made. These results confirm the local perspective from which previous spectroscopic assignments have been made. However, the inconsistency with the results from OD-EPR spectra remains.