Using analytical excited-state gradients, vibrational normal modes have been calculated at the minimum of the electronic excited-state potential energy surfaces for a set of extended conjugated molecules with different coupling between them. Molecular model systems composed of units of polyphenylene ethynylene (PPE), polyphenylenevinylene (PPV), and naphthacene/pentacene (NP) have been consider...

We report a molecular beam study of the effect of vibrational excitation on the physisorption of methane on a Pt(111) surface. Our experiments use a continuous molecular beam of CH4, prepared in its antisymmetic C−H stretch mode ν3 by infrared laser pumping via rapid adiabatic passage. Physisorbed CH4(ads) is detected on a Pt(111) surface by reflection absorption infrared spectroscopy. At a sur...

The electron impact vibrational excitation of H2 molecules physisorbed on a free-electron metal surface is studied theoretically at collision energies of a few eV. The role of the short-lived low-lying 2Su resonance is investigated. The electron scattering by a free H2 molecule is described by the R-matrix method and the corresponding results are used to model the electron scattering by the phy...

Electronic-vibrational dynamics in molecular systems that interact with an environment involve a large number of degrees of freedom and are therefore often described by means of open quantum system approaches. A popular approach is to include only the electronic degrees of freedom into the system part and to couple these to a non-Markovian bath of harmonic vibrational modes that is characterize...

A time-domain method for calculating vibrational band profiles that simultaneously takes into account both the diagonal frequency modulations (of individual oscillators in the system) and the off-diagonal (intermolecular) vibrational coupling is developed and applied to the OH stretching band of liquid water (neat liquid H2O). It is shown that the calculated spectral features of both the isotro...

Recent modeling of thermal nonequilibrium processes in simple molecules like hydrogen and nitrogen has indicated that rotational nonequilibrium becomes as important as vibrational nonequilibrium at high temperature. In this study, to analyze rotational nonequilibrium, the rotational mode is separated from the translational-rotational mode that is usually considered in two-temperature models. Th...

The 351 .l-nm photoelectron spectra of HFC=C:and F2C=C:are reported. Transitions from the anion ground state to the neutral singlet ground state and low-lying triplet states are observed. The electron affinity of difluorovinylidene is 2.255 (6) eV, and the triplet term energy is To(H 3A2 F,CC) = 0.924 (9) eV. In the singlet state of F2C=C:, vibrational progressions are observed at 510 (25), 905...

The vibrational energy relaxation of carbon monoxide in the heme pocket of sperm whale myoglobin was studied by using molecular dynamics simulation and normal mode analysis methods. Molecular dynamics trajectories of solvated myoglobin were run at 300 K for both the delta- and epsilon-tautomers of the distal His-64. Vibrational population relaxation times of 335 +/- 115 ps for the delta-tautome...

A new, accurate, global, mass-independent, first-principles potential energy surface (PES) is presented for the ground electronic state of the water molecule. The PES is based on 2200 energy points computed at the all-electron aug-cc-pCV6Z IC-MRCI(8,2) level of electronic structure theory and includes the relativistic one-electron massvelocity and Darwin corrections. For H2 O, the PES has a dis...

We report on Raman spectroscopy of few quintuple layer topological insulator bismuth selenide (Bi2Se3) nanoplatelets (NPs), synthesized by a polyol method. The as-grown NPs exhibit excellent crystalline quality, hexagonal or truncated trigonal morphology, and uniformly flat surfaces down to a few quintuple layers. Both Stokes and anti-Stokes Raman spectroscopy for the first time resolve all fou...