Theoretical study of hydrated Be2+ ions

Static and dynamic density functional investigation of hydrated beryllium dications

“…These frequencies are reported in [71 to be essentially identical, whereas a considerable splitting was also found in the study 161. These bending modes are red-shifted by about 100-150 cm-' when adding two H,O molecules, which is qualitatively similar to the findings on the MP3/3-21G level [7].…”

“…Adding two H 2 0 molecules to [Be(H,0)]2', we find a blue shift of = 200 cm-', or a factor of 5-6%, which coincides with the previous estimate based on ~~3/3-21G calculations [7]; we estimate that our overall error margins for the ionic clusters amount to roughly f50 cm-'. We also confirm that the HOH bending mode is essentially not affected by the two additional H 2 0 ligands.…”

An ab initio study of beryllium(II) hydration

“…This is denoted as [m + n], with m, n being the number of water molecules in the first and second hydration shells, respectively. We note little difference between the 3-21G * results of Hashimoto [10] and the 6-31G * results of Bock [11]. It seems that the effect of adding polarization functions to the basis set and of including correlation has only a small effect (<0.02 Å) on the Be-O distance.…”

“…After some early work by Kollman [8] and Probst [9], Hashimoto fully characterized their structures to be minima and also report 3-21G vibrational frequencies [10]. Bock and Glusker were the first to optimize at the correlated level, examined alternate partitionings of water between the first and second hydration spheres, and concluded that four-fold coordination was the preferred structural motif [11].…”

Computational studies on hydrates of alkaline-earth dications

“…The ions studied here are much larger than ~e " and the first hydration shell could easily accommodate six water molecules. To check the relative stabilities of the two possible distributions of the six water molecules around the central ion, full geometry optimization was done for the magnesium ion hexahydrate in T , and C, symmetries (the latter structure could be best written as [M~'+(H,O),](H~O),); following lwata and co-workers (24), the 3-21G* basis set was used. The M 8 -0 distance in the Ti, structure was found to be 2.075 A, shorter than the value obtained with the TZlP basis set, and the total hydration energy was 408 kcal/mol.…”