A statistical thermodynamic supermolecule-continuum study of ion hydration: Cell and shell methods

Free Energy Via Molecular Simulation: Applications to Chemical and Biomolecular Systems

“…The main limitation of the continuum theories is their inability to account for specific solute-solvent interactions such as the hydrogen bonding prevalent in aqueous solutions. This limitation has led to the development of a sequence of hybrid "supermolecule-continuum" type theories (200,201), of which the extreme is fully discrete molecular simulation. Warshel (233,234) and Warshel & Levitt (237) have performed a number of studies on this genre of biological molecules involving free energy estimates.…”

Ground states of molecules. 44. MINDO/3 calculations of absolute heat capacities and entropies of molecules without internal rotations

“…Since energies calculated by MINDO/3 are not accurate enough for the present purpose, we had to use one experimental value, i.e., the heat of reaction (AH) at 25 °C (298.15 K). 19 We then calculated the values of AH at other temperatures, using our calculated specific heats (Cp°) to estimate the specific heat of reaction (ACP) as a function of temperature together with Kirschoff s equation, AHT = //298 15 + fT (ACp)dT (9) J298.15 µ We also calculated the entropies of reaction ( 5) as a function of temperature from the corresponding MINDO/3 entropies (5°) of the reactants and products, and hence the free energy of reaction, AG: AGt=AHt-TASt (10) Table VII compares calculated and observed values of AGT for the six reactions at 300, 900, and 1200 K. The errors in AG are nearly all less than 1 kcal mol-1, the only exception being -13.9/ "M. Uchiyama, T. Tadas, and A. Amans,/. Phys.…”

Quantum mechanical calculation of thermodynamic functions of solvation of ammonium ions in water

“…[14] are also summarized in Table 1. For NH,', a calculated value of 11.0 kcal/mol is obtained compared with an experimental value of 6.6 kcal/mol reported by Aue et al (1).…”

“…A complete thermodynamic picture of the solvation process may be achieved only, within this approach, by including Monte Carlo simulation techniques in order to account for the temperature averaging effects (14).…”