Molecular geometries and energetics of metal-containing systems using an improved ASED-MO model: a systematic test to group 1 and 2 metal containing systems in the gas phase

Theoretical Study of RbOH, CsOH, FrOH, and Their Cations: Geometries, Vibrational Frequencies, and the Ionization Energies

“… who obtained a value of 83 ± 2 kcal mol -1 at the CISD level of theory that is between our value and the Gurvich et al recommendation. Stiakaki et al calculate D e = 82 kcal mol -1 , and Mestdagh and Visticot 22 obtain D 0 = 76 kcal mol -1 , in excellent agreement with the value obtained herein. Our D 0 value may straightforwardly be converted to a Δ H f 298 value, yielding Δ H f 298 (RbOH) = −50 kcal mol -1 , which is less than the value of −57 ± 1 kcal mol -1 recommended in ref .…”

“…We also note that Bauschlicher et al . obtained a value of 87 ± 2 kcal mol -1 , which is close to the recommendation of Gurvich et al Stiakaki et al calculate D e = 81 kcal mol -1 , and Mestdagh and Visticot 22 obtain D 0 = 81 kcal mol -1 . Both of these are in good agreement with the value obtained herein.…”

“…Early studies by Nemukhin and Stepanov 20 employing the diatomics- in-molecules (DIM) approach with two parametrizations indicated ω 1 = 332 or 335 cm -1 and ω 2 = 676 or 700 cm -1 , i.e., the bending frequency being significantly higher than the Rb−O stretch. The atom superposition and electron delocalization (ASED) model of Stiakaki et al yielded structural and energetic information with an Rb−O bond length of 2.345 Å, while the electrostatic model of Mestdagh and Visticot 22 yielded the dipole moment and the dissociation energy. The only ab initio study appears to be that of Bauschlicher et al, who fixed the O−H bond distance and derived the Rb−O bond length and the ω 1 vibrational frequency at the SCF and CISD levels of theory, employing a (18s14p11d4f/12s10p5d3f) basis set for Rb.…”

“…There has been an electrostatic model study by Mestdagh and Visticot 22 and an ASED molecular orbital study by Stiakaki et al . Reference 21 reported some structural and energetic properties, with the Cs−O bond length being derived as 2.447 Å. The only ab initio study so far reported is that from Bauschlicher and co-workers .…”

Aqua dissociation nature of cesium hydroxide

“…20 They reported the Cs-OH bond distance to be 2.419 Å at fixed O-H bond length. Then in 1994, Stiakaki et al 24 did a molecular orbital study and reported a Cs-OH bond distance of 2.447 Å. The latest work was done by Lee and Wright 25 in which they report the Cs-OH bond distance to be 2.635 Å with CCSD͑T͒ level of theory with LANL2͓9s8 p3d2 f ͔ basis set for Cs and aug-cc-pVTZ basis set for O and H. Although our DFT and MP2 results are rather different from the electron diffraction study by Girichev et al 26 and the latest ab initio study by Lee and Wright, 25 our results are very close to the earlier theoretical and experimental results, off only by 0.055 Å with B3LYP and 0.069 Å with MP2 compared to the microwave study 22 ͑see Table I͒.…”