4 f 2 /4f6p configuration interaction in LiYF 4 </…
1997; American Physical Society; Volume: 55; Issue: 6 Linguagem: Inglês
10.1103/physreva.55.4150
ISSN1538-4446
Autores Tópico(s)Glass properties and applications
ResumoIn two other papers [M. D. Faucher, O. K. Moune, D. Garcia, and P. Tanner, Phys. Rev. B 53, 9501 (1996); M. D. Faucher and O. K. Moune, J. Alloys Compounds (to be published)], it was shown that the introduction of the ${5\mathrm{f}}^{\mathrm{n}}$/${5\mathrm{f}}^{\mathrm{n}\mathrm{\ensuremath{-}}1}$7p (or ${4\mathrm{f}}^{\mathrm{n}}$/${4\mathrm{f}}^{\mathrm{n}\mathrm{\ensuremath{-}}1}$6p) configuration interaction eliminated large discrepancies in the crystal-field analysis of (i) ${\mathrm{U}}^{4+}$ (${5\mathrm{f}}^{2}$) in ${\mathrm{Cs}}_{2}$${\mathrm{UBr}}_{6}$ and ${\mathrm{Cs}}_{2}$${\mathrm{ZrBr}}_{6}$, for which the least root-mean-square deviation between experimental and calculated energy levels falls down from 241 to 56 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$, and (ii) ${\mathrm{Nd}}^{3+}$ in ${\mathrm{Nd}}_{2}$${\mathrm{O}}_{2}$S, for which the discrepancy of the $^{2}\mathrm{H}$(2${)}_{11\mathrm{/}2}$ level is eliminated by the configuration interaction with the excited ${4\mathrm{f}}^{2}$6p configuration. The demonstration is now extended to ${\mathrm{Pr}}^{3+}$ and seems to be of general application. For ${\mathrm{LiYF}}_{4}$:${\mathrm{Pr}}^{3+}$ the mean deviation is divided by more than 2 by utilizing an interaction matrix including 4f6p in addition to the ground configuration ${4\mathrm{f}}^{2}$.
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