Aqueous solvation models for ions of the 2nd group.
Abstr Pap - Am Chem Soc 2004 Mar; 227(Part 1):INOR-580
Heats of hydration for the Group II metal ions are fairly large. Experimental values for Be2+, Mg2+ and Ca2+ are -584, -456 and -381 kcal/mol, respectively. The ability of CHARMM and AMBER force fields to effectively reproduce these large values was tested. Free energies of hydration were computed using the free-energy perturbation method. A thorough variation of the Lennard-Jones van der Waals parameters showed that both radial distribution functions and the energetics of Mg2+ and Ca2+ solvation can be reasonably reproduced within the framework of nonpolarizable force fields. However, this approach fails for the smallest representative of Group II Be2+. We demonstrate using the TlP3P water model that it is not possible to simultaneously model both solvation effects accurately. The physical/chemical reasons for this are discussed, and compromise strategies of Be2+, modeling are suggested.
Metals; Metal-compounds; Analytical-methods; Analytical-processes; Analytical-chemistry
Abstract; Conference/Symposia Proceedings
Abstracts of papers - American Chemical Society