Hydration structures of barium ions: Ab initio molecular dynamics simulations using the SCAN meta-GGA density functional and EXAFS spectroscopy studies

Hydration structures of barium ion (Ba2+) were studied by ab initio molecular dynamics using the strongly constrained and appropriately normed (SCAN) meta-generalized gradient approximation (GGA) exchange-correlation (XC) functional and extended X-ray absorption fine structure spectroscopy, which showed consistent results for the static properties. The result obtained with SCAN was compared with these with the Perdew–Burke–Ernzerhof (PBE) and Becke–Lee–Yang–Parr (BLYP) GGA XC functionals and the functionals with the Grimme’s dispersion correction (PBE-D3 and BLYP-D3). The comparison revealed the importance of the dispersion interaction for the static and dynamic properties of the Ba2+ hydration structures.