The mode-specific vibrational energy relaxation of the amide I' and amide II' modes in NMA-d(1)/(D(2)O)(n) (n = 0-3) clusters were studied using the time-dependent perturbation theory at the B3LYP/aug-cc-pvdz level. The amide modes were identified for each cluster based on the potential energy distribution of each mode. The vibrational population relaxation time constants were derived for the a...

%$& in the 5 17 GHz region for Kr-SH, respectively. In these spectra ' -type doublings and hyperfine splittings associated with the H nuclei have been observed. Although the spectral pattern of Kr-SH is relatively regular, that of Ne-SH is fairly irregular with the dependence of the ' -type doubling very different from other Rg-SH or Rg-OH species. In the present analysis, we used a program sys...

An improved three-dimensional potential energy surface for the H(2)-Kr system is determined from a direct fit of new infrared spectroscopic data for H(2)-Kr and D(2)-Kr to a potential energy function form based on the exchange-Coulomb model for the intermolecular interaction energy. These fits require repetitive, highly accurate simulations of the observed spectra, and both the strength of the ...

The infrared photodissociation spectrum of the degenerate asymmetric CH stretch (n3) vibration of the CH3 –He ionic complex has been recorded. The rotational structure and vibrational frequency of the observed transition are consistent with a p-bonded C3v cluster geometry where the He ligand is attached to the 2pz orbital of the central C atom of CH3 1 . The intermolecular bond in the ground vi...

The potential energy surface of an off-lattice model protein is characterized in detail by constructing a disconnectivity graph and by examining the organisation of pathways on the surface. The results clearly reveal the frustration exhibited by this system and explain why it does not fold efficiently to the global potential energy minimum. In contrast, when the frustration is removed by constr...

A five-dimensional potential energy surface (PES) for the interaction of a rigid methane molecule with a rigid nitrogen molecule was determined from quantum-chemical ab initio calculations. The counterpoise-corrected supermolecular approach at the CCSD(T) level of theory was utilized to compute a total of 743 points on the PES. The interaction energies were calculated using basis sets of up to ...