A hybrid approach for simulating proton and hydride transfer reactions in enzymes is presented. The electronic quantum effects are incorporated with an empirical valence bond approach. The nuclear quantum effects of the transferring hydrogen are included with a mixed quantum/classical molecular dynamics method in which the hydrogen nucleus is described as a multidimensional vibrational wave fun...

__________________ Abstract _____________________________________________________________________ The conformational stability, intramolecular H-bond strength, energy barriers, vibrational frequencies and gas-phase basicities of fourteen most stable conformers of ethanolamine in gas phase and in aqueous and carbon tetrachloride solutions have been investigated at B3LYP and MP2 level with 6-311+...

Localization to the ground state of axial motion is demonstrated for a single, trapped atom strongly coupled to the field of a high finesse optical resonator. The axial atomic motion is cooled by way of coherent Raman transitions on the red vibrational sideband. An efficient state detection scheme enabled by strong coupling in cavity QED is used to record the Raman spectrum, from which the stat...

We report the first spectroscopic observation of and vibrational predissociation dynamics for ArBr(2). Measurements are reported for the linear and T-shaped isomers with time and frequency resolution near the Fourier limit of a 15 ps pulse. For the T-shaped isomer, the Ar-Br(2) bond energy D(0) for the B state, nu(')=19, is found to be 200 cm(-1), yielding a D(0)(X) value of 213 cm(-1). Product...

We propose an alternative to the usual time–independent Born–Oppenheimer approximation that is specifically designed to describe molecules with Hydrogen bonds. In our approach, the masses of the Hydrogen nuclei are scaled differently from those of the heavier nuclei, and we employ a specialized form for the electron energy level surface. Consequently, anhar-monic effects play a role in the lead...

Introduction In this experiment you will examine the energetics of vibrational and rotational motion in the diatomic molecule HCl. The experiment involves detecting transitions between different molecular vibrational and rotational levels brought about by the absorption of quanta of electromagnetic radiation (photons) in the infrared region of the spectrum. The introductory discussion consists ...

MIPAS is a limb viewing fourier transform spectrometer operating in the infra-red. It scans the tangent altitude range 6-68 km at a vertical resolution of approximately 3km. CO has various natural and anthropogenic sources including forest fires and industry. In the troposphere, CO is the main sink of the principal oxidising agent the hydroxyl radical and so reduces its capacity for the removal...

We report the complete assignment of the vibrational spectrum of dipalmitoylphosphatidylcholine (DPPC), which belongs to the most ubiquitous membrane phospholipid family, phosphatidylcholine. We find that water hydrating the lipid headgroups enables efficient energy transfer across membrane leaflets on sub-picosecond time scales. The emergence of spatially extended vibrational modes upon hydrat...

The thermodynamic functions such as enthalpy (H), Gibbs free energy (G) and entropy (S) of Serineand Threonine amino acids were theoretically studied at different condition (solvents andtemperatures) by using Gussian o3, software. First, the structural optimization of isolated Serine andThreonine were done in the gas phase by using the Hartree-Fock (HF) level of theory with 3-21G, 6-31G and 6-3...