Theoretical investigation of thermochemical properties of cesium borates species

The coupled cluster single-double and perturbative triple (CCSD(T)) approach within highly correlated wave functions has been performed to better understand the thermochemical properties of gaseous cesium borates. Several corrections were added for core-valence correlation and relativistic effects. Structural parameters have been optimized with the B3LYP/aug-cc-pVTZ level of theory. The standard molar entropies and heat capacities at constant pressure have been also determined at the same level of theory. ΔfH°298K have been obtained for the studied cesium borates species using a set of three reactions. The standard enthalpies at 298 K for CsBO2 and Cs2B2O4 are estimated to be (−689.0 ± 3.8) and (−1578.5 ± 7.0) kJ mol−1, respectively. They are in good agreement with available literature data. Numerical simulations show that in a nuclear context, CsBO2 will be formed preferentially to CsOH in steam atmosphere for high temperature.