Ab initiomolecular dynamics studies of hydroxide coordination of alkaline earth metals and uranyl

Abstract

Proton dynamics of alkaline earth and uranyl hydroxide solutions are simulated, revealing substantial dependence on ion charge density.

Assessing the Intrinsic Strengths of Ion–Solvent and Solvent–Solvent Interactions for Hydrated Mg2+ Clusters

“…From the k a cum values of the implicitly solvated clusters, as shown in Table 4, we observed the implicit addition of outer shells to [Mg(H 2 O)n] 2+ (n = 1-6) clusters to increase in stability alongside increasing CN, the results revealing a CN of 6 to result in the most stable configuration due to the Mg-O and HB interactions. The CN of 6, as suggested from local mode analysis, agrees with recent experimental [16,19,21,22,24] and computational works [20,32,34,39,[41][42][43][44]46,47,49,51]. In this work, via the utilization of cumulative local mode stretching force constants k a cum , we observed the divalent Mg ion to coordinate with up to six water molecules, whereas in our previous work regarding hydrated calcium clusters, the divalent Ca ion was observed to undergo coordination with up to eight water molecules [106].…”

“…Moreover, the 3), a CN of 5, with respect to a CN of 6, is observed to result in more stable configurations. It is noted that current ab initio molecular dynamics simulations conducted by Lynes and co-workers revealed a small percentage of the CN for Mg 2+ to be 5 [42]. ), m = 2-4), it is inferred that clusters 9-11 are more likely to be present.…”

“…Numerous solid-state structures of inorganic composites have validated the existence of the six-coordinated structure ([Mg(H 2 O) 6 ] 2+ ) [31]. Theoretical investigations into the solvation of Mg 2+ span across molecular dynamic (MD) simulations [20,[32][33][34][35], Monte Carlo simulations [32,[36][37][38], Car Parrinello molecular dynamic simulations (CPMD) [39], effective fragment potential (EFP) calculations [40], ab initio molecular dynamics (AIMD) [28,[41][42][43], density functional theory (DFT) [41,[44][45][46][47][48][49][50], Møller-Plesset secondorder perturbation theory (MP2) [41,44,47,49], coupled cluster theory with singles, double, and perturbative triples (CCSD(T)) [47,49], and Born-Oppenheimer molecular dynamics (BOMD) [51]; among these studies, a CN of 6 has been reported. However, the DFT study of Pavlov and co-workers has suggested that the Mg 2+ ion forms stable configurations when coordinated to seven water molecules [52] [41,47]; Bai et al also reported that the first hydration shell influences the charge transfer between the divalent magnesium cation and outer solvent shells [41].…”

“…Moreover, by comparing the k a cum values of cluster 9 (i.e., [Mg(H 2 O) 5 ] 2+ -3 (H 2 O)) and 10 (i.e., [Mg(H 2 O) 5 ] 2+ -4 (H 2 O)) to clusters 15 (i.e., [Mg(H 2 O) 6 ] 2+ -3 (H 2 O)) and 16 (i.e., [Mg(H 2 O) 6 ] 2+ -4 (H 2 O)) (see Table3), a CN of 5, with respect to a CN of 6, is observed to result in more stable configurations. It is noted that current ab initio molecular dynamics simulations conducted by Lynes and co-workers revealed a small percentage of the CN for Mg 2+ to be 5[42].Because 9-11 ([Mg(H 2 O) 5 ] 2+ -m(H 2 O), m = 2-4) clusters…”

Electrical Conductance And Theoretical Study Of Glutamic Acid In Different Solvents at 310.16k

“…In addition to estimating multiple descriptors across all of the above approaches. In addition, important reactions in the fields of chemistry [19][20][21], chemical engineering [22,23] and biology are the dissociation and interaction of ions in a polar solvent, such as water. Therefore, the conductance behaviour of glutamic acid in water, methanol and ethanol at 37oC was also studied and used Lee-Wheaton equation Conductance measurements were analyzed for NaClO4 and C6H5COONa solutions in 298.15 K acetonitrile + water.…”