Structure and stability of Na+Xen clusters

Cs+ Solvated in Hydrogen—Evidence for Several Distinct Solvation Shells

“…Facets appear when heavy, highly polarizable rare atoms grow around an ion; closure of these subshells leads to anomalies in dissociation energies and ion abundances. 34,35 Thus, anomalies in the present work are likely to indicate the completion of solvation shells. We will first focus on the set of anomalies at n = 12, 32, and 44.…”

“…Although highly speculative, we note that the preferred structure of a cluster ion with eight solvent atoms or molecules is, quite often, the square antiprism. This structure appears in recent theoretical studies of Ar n Na + and Xe n Na + by Spiegelman and co-workers. , The closed-shell (H 2 ) 8 Na + also adopts this structure, but for (H 2 ) 8 Li + , the square antiprism seems to be less stable than the octahedral (H 2 ) 6 Li + with two additional H 2 located in a second shell. , …”

“…Observation 1 suggests that incomplete second and higher solvation shells in (H 2 ) n Cs + are not likely to exhibit island growth, or facets. Facets appear when heavy, highly polarizable rare atoms grow around an ion; closure of these subshells leads to anomalies in dissociation energies and ion abundances. , …”

“…This structure appears in recent theoretical studies of Ar n Na + and Xe n Na + by Spiegelman and co-workers. 35,36 The closed-shell (H 2 ) 8 Na + also adopts this structure, 5 but for (H 2 ) 8 Li + , the square antiprism seems to be less stable than the octahedral (H 2 ) 6 Li + with two additional H 2 located in a second shell. 4,7 Even if the most stable structure of (H 2 ) 8 Cs + were the square antiprism, why would it feature an enhanced dissociation energy?…”

Helium Droplet Mass Spectrometry

“…The bond nature of AuRg m + (m = 1, 2) is predicted to exhibit significant covalent character for Rg = Kr and Xe, slight covalent character for Ar [319,329,[333][334][335], but to be entirely physical for Ne [328,333,335]. Alkali metal ions embedded in rare gas clusters A + Rg m , can be used as an entirely physically bound model system, but no anomalies at m = 2 can are predicted for A = Li-K and Rg = Ar, Xe [336][337][338][339]. It is conceivable that the theoretical treatment of AuNe m + is inaccurate, failing to reproduce the observed anomaly at m = 2, which might also infer that the character of binding in AuNe m + is not entirely physical in the end.…”