Modern Chemistry & Applications

On the theory of interaction potentials in ionic crystals (II): Applications to the thermodynamics of the elpasolite Cs2KLnCl6 crystals

9^th Global Chemistry Congress

July 23-24, 2018 | Lisbon, Portugal

Roberto Acevedo and A Soto-Bubert

Universidad of Chile, Chile
San Sebastián University, Chile

Posters & Accepted Abstracts: Mod Chem Appl

Abstract:

A rather complete and informative analysis of the intermolecular and intramolecular potentials is put forward with reference to the lanthanide type systems, such as Cs2KLnCl6, in the Fm3m, space group. The current study is focused on the trivalent lanthanide ions (Ln), characterized by atomic numbers in the atomic number interval: . A particular situation occurs in both extreme of the series, say for 58Ce:[54Xe]4 f 25d 06s2 and 71Lu:[54Xe]4 f 145d 16s2, respectively. The 13 trivalent lanthanide ions, moving along with the series from Ce+3 to Lu+3, for these ions the 4f shell is not fully occupied and therefore the physical and chemical properties are indeed, somehow challenging and interesting to examine using structural, spectroscopic and theoretical methods and model calculations. We have elaborated some physical models and carried out a substantial amount of calculations, so as to estimate the reticular energy and also employing a thermodynamic Born-Haber cycle, we have been able to make some sound predictions and numerical estimation of heat formations for the above series of lanthanide type crystals. The calculated energy values associated with these observations seems to be most reasonable and these follow the expected trends, as may be anticipated from theoretical and experimental grounds. Both, the advantages and disadvantages of the current model calculation have been tested against other previous calculations performed. Some convergence tests as well as some master equations are employed to account for the various contributions to the total energy. The Born-Mayer-Buckingham potential is carefully examined with reference to these lanthanide type crystals Cs2KLnCl6. Finally, the most likely sources for improvement are carefully discussed.

Biography :

E-mail: roberto.acevedo.llanos@gmail.com