We report the first experimental demonstration of vibrational mode-dependent enhancement in photodissociation and photoionization of a seven atom molecule, methylamine (CH(3)NH(2)). The fundamental C-H stretches and the overtones or combinations of CH(3) bends were prepared via stimulated Raman excitation (SRE) prior to their 243.135 nm one-photon dissociation or two-photon ionization. The phot...

Absolute measurements are presented for the excitation of the 3 vibrational mode in CF4 by positron and electron impact from 0.1 to 2 eV. To minimize systematic differences, these measurements were made using the same trap-based electron or positron beam, associated experimental apparatus, and procedures. Unlike other vibrational excitation cross sections studied to date, the near-threshold cro...

Nuclear resonance vibrational spectroscopy (NRVS; also known as nuclear inelastic scattering, NIS) is a synchrotron-based method that reveals the full spectrum of vibrational dynamics for Mössbauer nuclei. Another major advantage, in addition to its completeness (no arbitrary optical selection rules), is the unique selectivity of NRVS. The basics of this recently developed technique are first i...

Highly accurate quantum-mechanical calculations az presented for highly excited vibrational states of HzO. The vibration Hamiltonian operator Hvib for a nonlinear triatomic molecule is given in Radau coordinates. A direct product basis is chosen, and the Hvib matrix is evaluated in the discrete variable representation (DVR) for the symmetrized Radau coordinates. Vibrational eigenstates are comp...

We introduce a point of view for treating the dynamical tunneling splitting of symmetric local mode vibrational states in ABA molecules (A = H typically) which is the one we have employed in treating the vibrational spectroscopy of CH overtones in molecules such as (CXs),YCCH. Namely, the vibrational coupling corresponding to the dynamical tunneling in semiclassical mechanics via many intermedi...

Recent calculations on the formation of self-trapped amide group vibrational states in -helical polypeptides J. Chem. Phys. 124, 134907 2006 are extended to the amide N–H normal mode vibrations. First, the adiabatic N–H vibrational singleand two-exciton states are examined by treating the longitudinal chain coordinates as parameters. Then, in using the multiconfiguration time-dependent Hartree ...

The paper presents the results for water confined in a human breast cancerous tissue, a single stranded DNA, a double stranded DNA and in phospholipids (DPPC—D--Phosphatidylcholine, dipalmitoyl). The interfacial water in DNA and lipids is represented by a double band in the region of the OH stretching mode of water corresponding to the symmetric and asymmetric vibrational modes, in contrast to...

Quasiclassical, direct dynamics trajectories, calculated at the B3LYP/6-31G** level of the theory, have been used to study the energy transfer dynamics and collision-induced dissociation ~CID! of formaldehyde cation in collisions with Ne. Effects of varying collision energy were probed for ground state H2CO , and H2CO 1 with excitation in three different vibrational modes: n6 1 ~in-plane CH2 ro...