| Autor: |
Naleway, Conrad, Seth, Michael, Shepard, Ron, Wagner, Albert F., Tilson, Jeffrey L., Ermler, Walter C., Brozell, Scott R. |
| Předmět: |
|
| Zdroj: |
Journal of Chemical Physics; 4/1/2002, Vol. 116 Issue 13, p5481, 13p, 4 Charts, 7 Graphs |
| Abstrakt: |
The first three ionization potentials of europium and the f-f spectroscopy of the two lowest multiplets of Eu[sup +3] have been calculated using ab initio spin-orbit configuration interaction techniques. To accomplish this, a new averaged relativistic effective core potential has been developed which leaves only the 5s, 5p, and 4f in the valence space. A series of configuration interaction calculations were carried out up through single and partial double excitations with a double-zeta quality basis set. The computed ionization values have an absolute error of about 0.1 eV from the experimental values. The computed f-f spectroscopy for the lowest 7F multiplet of Eu[sup +3] has a RMS error with experiment of about 100 cm[sup -1]. The computed f-f spectroscopy for the first excited [sup 5]D multiplet has a higher RMS error of about 350 cm[sup -1]. The computed center of gravity separation between the [sup 5]D-[sup 7]F multiplet is underestimated by 750 cm[sup -1]. Comparisons between non-spin-orbit and spin-orbit configuration interaction calculations for the separations of the centers of gravity of multiplets are very favorable up through single and double excitations with differences of a tenth of an eV or less. The spin-orbit configuration interaction calculations are among the largest ever performed for lanthanides, with expansion lengths in excess of 1.9 million double-group-adapted functions. The calculations were achieved by application of a new parallel spin-orbit configuration interaction component in the COLUMBUS Program System. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
