标题：Extended X-ray absorption fine structure spectroscopy measurements and ab initio molecular dynamics simulations reveal the hydration structure of the radium(II) ion
摘要：SummaryRadium is refocused from the viewpoint of an environmental pollutant and cancer therapy using alpha particles, where it mainly exists as a hydrated ion. We investigated the radium hydration structure and the dynamics of water molecules by extended X-ray absorption fine structure (EXAFS) spectroscopy andab initiomolecular dynamics (AIMD) simulation. The EXAFS experiment showed that the coordination number and average distance between radium ion and the oxygen atoms in the first hydration shell are 9.2 ± 1.9 and 2.87 ± 0.06 Å, respectively. They are consistent with those obtained from the AIMD simulations, 8.4 and 2.88 Å. The AIMD simulations also revealed that the water molecules in the first hydration shell of radium are less structured and more mobile than those of barium, which is an analogous element of radium. Our results indicate that radium can be more labile than barium in terms of interactions with water.Graphical abstractDisplay OmittedHighlights•Extended X-ray absorption fine structure (EXAFS) measurement revealed the hydration structure of radium ion•Ab initiomolecular dynamics (AIMD) simulation brought consistent results•AIMD revealed the structural and dynamic properties of the water molecules•The hydration structure of radium ion is more labile than that of barium ionNuclear structure; Nuclear spectroscopy; Molecular dynamics
