Prediction of pressure-induced redshift of f1→d(t2g)1 excitations in Cs2NaYCl6:Ce3+ and its connection with bond-length shortening

Abstract

Quantum chemical calculations including embedding, scalar relativistic, and dynamic electron correlation effects on Cs 2 NaYCl 6 : ͑CeCl 6 ͒ 3− embedded clusters predict ͑i͒ redshifts of the f 1 → d͑t 2g ͒ 1 transition with pressure and ͑ii͒ bond-length shortening upon f → d͑t 2g ͒ excitation. Both effects are found to be connected which suggests that new high-pressure spectroscopic experiments could reveal the sign of the bond-length change.

Relation between high-pressure spectroscopy andfn−1d1excited-state geometry: A comparison between theoretical and experimental results inPascual1, Barandiarán2, Seijo3 2007Phys. Rev. BSelf Cite20040View full textAdd to dashboardCite

“…͑1͒, in line with the results of Ref. 3 and completes the picture for the relative positions of the different states in eightfold cubic coordination: R e ͓f n−1 d͑e g ͒ 1 ͔ ഛ R e ͓f n ͔ ഛ R e ͓f n−1 d͑t 2g ͒ 1 ͔. As in sixfold octahedral coordination, the transition to the lowestlying 4f n−1 5d 1 states shortens the impurity-ligand bond length and the transition to the highest-lying 4f n−1 5d 1 states lengthens it.…”

“…[1][2][3] This result is quite general, as it has been obtained for different halide ligands ͑F, Cl, Br͒, environments ͑crystals, liquid solutions, gas phase͒, oxidation states of the f element ͑III, IV͒, and number of f electrons. 1,2 However, it is in contradiction with the widespread assumption that the f n → f n−1 d 1 excitations lengthen the impurity-ligand bond distance.…”

“…7 Finally, let us remark the fact that the rule of thumb derived in Ref. 3 to predict the sign of the change of a transition with pressure, based on calculations on octahedral Ce 3+ clusters ͑4f 1 ͒ ͑use the configurational diagram for ambient pressure and assume that the effects of pressure correspond to moving inward across the R axis͒, can be equally used in this case ͑cubic 4f 6 ion͒, as it can be deduced from Fig. 3.…”

“…As an alternative, it has been recently proposed that experimental spectroscopic studies under high hydrostatic pressure could be used to indirectly prove or reject the predicted bond length shortening upon the lowest f n → f n−1 d 1 excitations, 3 because quantum chemical simulations of pressure effects on Cs 2 NaYCl 6 : ͑CeCl 6 ͒ 3− , which included embedding effects, scalar relativistic effects, and dynamical electron correlation, have shown that the bond length shortening upon the f 1 → d͑t 2g ͒ 1 excitation and the predicted redshift of the f 1 → d͑t 2g ͒ 1 transition with pressure in this system are related. 3 The theoretical analyses 2,3 lead to the conclusion that the sign of the bond length change upon i → f excitation determines the sign of the slope of the transition energy with pressure:…”

“…3 The theoretical analyses 2,3 lead to the conclusion that the sign of the bond length change upon i → f excitation determines the sign of the slope of the transition energy with pressure:…”