. Author manuscript; available in PMC: 2006 Mar 22.

Published in final edited form as: J Am Chem Soc. 1999 Feb 24;121(7):1565–1573. doi: 10.1021/ja982653+

Table 8.

Reverse Activation Barrier of the Proton-Transfer Reaction M²⁺(H₂O)₂ → MOH⁺ + H₃O⁺, Calculated in Three Different Ways^a

M	B3LYP	E_cou	E_sb
Be	380.7	567.3	700.1
Mg	198.6	259.3	193.6
Ca	204.7	247.8	196.5
Sr	189.9	232.1	175.2
Ba	180.5	222.4	165.5

B3LYP denotes the difference between TS2 and the products, E_cou is the Coulomb energy of two positive charges at the M–O2 distance, and E_sb is the Coulomb energy of H₃O⁺ estimated in a multipole environment according to Figure 4b and eq 8.