Ab initio studies of electron correlation in rare-earth ions. I. Intrashell correlation for 4f²in Pr³⁺

The calculation of f-f spectra of lanthanide and actinide ions by the MCDF-CI method

“…The f-f spectra of U 4+ and Pr 3+ are relatively simple and have been calculated previously [4][5][6][7][8][9][10][11][12][13] with varying degrees of success in reproducing the experimental spectra. The main goal of this section is not so much to match or improve upon the accuracy achieved in these calculations but rather to analyse how the most accurate results can be obtained for these ions using the MCDF-CI method.…”

“…Due to these difficulties, calculations of f-f spectra remain extremely challenging and relatively few investigations have been published in the last few years. The f 2 species Pr 3+ and U 4+ have been studied a number of times [4][5][6][7][8][9][10][11][12][13] but work on more complex systems has been limited to the inclusion of a small amount of electron correlation or a consideration of only the lowest few excited states [10][11][12][13][14][15][16][17].…”

Electron correlation effects on thef6-manifold of the Eu3+ impurity in Ba2 GdNbO6

“…It was found by Visser et al that atomic electron correlation had to be taken into account to get an accurate description of the transitions between the ' 0 and 7F states of the ion. The importance of atomic correlation was also confirmed by Jankowski and Sokolowski [5] in their studies of the Pr3+ ion. In the Pr3+ case, they showed that the correlation effect represented by the double excitations from 4d --f 4f is very important.…”