Alejandro Ramírez-Solís (prof invité LPCNO) : Quantum chemical and periodic studies of Poly-oxygen systems : from O4 and (O2)4 to the solid high pressure phases (IRSAMC - 23 septembre 2013)

Alejandro Ramírez-Solís, Depto. de Física, Facultad de Ciencias,
Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos - 62209 México
- (Professeur invité LPCNO)

Salle de séminaire du 3ème étage, Bât. 3R1B4, 14h00

Abstract :
We shall present an overview of quantum theoretical results on molecular polyoxygen systems such as O4 and (O2)4. While the former is relevant for the oxygen cycle in the upper atmosphere, the second has been found as the unit cell in the ε and superconducting dzeta ζ phases of high pressure solid oxygen.

Emphasis will be placed on the study of the structural and electronic properties of these high pressure phases using periodic ab initio and Density Functional Theory based methods with gaussian atomic basis sets. It will be shown that the strong multireferential character of the non-magnetic ground state decreases with pressure and that only one hybrid exchange-correlation functional can correctly describe the epsilon-dzeta phase transition pressure and its associated electronic features. We will also discuss some of the questions that arise from the present results as well as the perspectives and future research lines.

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