Chemical behavior of strontium and magnesium oxalates at high-pressure

We report theoretical and experimental investigations on the structure of strontium and magnesium oxalates at high-pressure. Both systems have shown progress in the generation of CO₂ and in the synthesis of high-energy polymeric carbon monoxide after X-ray irradiation. It has been previously proposed that X-ray irradiation may facilitate photochemical reactions such as: SrC₂O₄ +hv -> SrCO₃ +CO₂ + poly-CO (MgC₂O₄ +hv -> MgO + CO₂ + poly-CO) [1]. Density functional perturbation theory was used to calculate the zone center optical phonons and to identify the vibration modes in term of atomic displacements. The simulations were compared to previous EXAFS and IR spectroscopic studies [1] in an effort to elucidate the chemical structure. Additional calculations of the phonon dispersion and density of states, as well as the electronic band structure were performed to gain better insight into the phase behavior in strontium and magnesium oxalates.
[1] M. Pravica, E. Evlyukhin, P. Cifligu, B. Harris, N. Chen, Y. Wang, Chemical Physics Letters 686, pp. 183-188 (2017).