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A new study uses laser-flash photolysis to investigate the Arrhenius functions for cyclicisations of the alpha-phenyl-substituted cyclopropylcarbinyl radicals.

Relative energetics of several alanine tetrapeptide conformations were determined. Results have shown that the large errors in hydration free energies in a given series in continuum-dielectric calculations could be explained by the inaccuracy of the potential functions in reproducing quantum chemical pair hydrogen bonding energies. It was indicted that the force fields that use fixed atom-centered charges will not reproduce energetic trends.

The evaluation of intermolecular interactions is addressed by assessing the applicability of van der Waals interactions of rare-gas atoms for the representation of van der Waals nonbonded interactions in molecular mechanics force fields. The reduced form of the Buf-14-7 distance-buffered potential can copy the reduced rare-gas potentials over a wide range of interatomic separations, unlike the Lennard-Jones and Exp-6 potentials. Alternative 'cubic-mean' and HHG combination rules for minimum-energy separations and well depths are also proposed.