Direct measurements of the lifetimes of He(79)Br(2) and Ne(79)Br(2) B-state vibrational levels 10 < or = nu' < or = 20 have been performed using time-resolved optical pump-probe spectroscopy. The values do not obey the energy gap law for direct vibrational predissociation. For both molecules, the dissociation rate for nu'=11 is much faster than for nu'=12, and the nu'=13 rate is also faster tha...

Previous spectroscopically determined potentials for both H216O and NO2 are discussed. It is shown that a recent H216O potential energy surface due to D. Xie and G. Yan (1996. Chem. Phys. Lett. 248, 409), which was determined by fits to vibrational term values alone and was claimed to be more accurate than other published spectroscopically determined potentials for this system, actually gives u...

The collision-induced electronic energy transfer that occurs when I 2 in the E(0 g ϩ) ion-pair electronic state collides with ground electronic state I 2 has been investigated. We prepare I 2 in single rotational levels in vϭ0 of the E state using two-color double resonance laser excitation. The resulting emission spectrum shows that the nearby (⌬T e ϭϪ385 cm Ϫ1) D(0 u ϩ) electronic state is po...

We report high-resolution anion photoelectron spectra of the cryogenically cooled cyanomethide anion, CH2CN(-), and its isotopologue, CD2CN(-), using slow photoelectron velocity-map imaging (SEVI) spectroscopy. Electron affinities of 12 468(2) cm(-1) for CH2CN and 12 402(2) cm(-1) for CD2CN are obtained, demonstrating greater precision than previous experiments. New vibrational structure is res...

Resonantly-enhanced one-color two-photon ~111! ionization spectra of jet-cooled methylamines (CH3NH2 and CH3ND2) reveal the vibrational structures of these molecules in predissociative à states. Rotational fine structure is clearly resolved for CH3ND2 at the origin and first wagging vibrational level in the excited state. The spectral linewidth becomes homogeneously broadened to give only vibra...

Potential energy functions (PEFs) of the X (1)A(') and A (1)A(") states of HSiF have been computed using the coupled-cluster single-double plus perturbative triple excitations and complete-active-space self-consistent-field multireference internally contracted configuration interaction methods, respectively, employing augmented correlation-consistent polarized-valence quadruple-zeta basis sets....

Variational rotational-vibrational quantum chemical computations are performed for the F(-)-CH4 and F(-)-CH2D2 anion complexes using several reduced-dimensional models in a curvilinear polyspherical coordinate system and utilizing an accurate ab initio potential energy surface (PES). The implementation of the models is made practical by using the general rovibrational code GENIUSH, which constr...

We present new vibrational (infrared) planar laser-induced fluorescence (PLIF) imaging techniques for CO(2) that use a simple, inexpensive, high-pulse-energy transversely excited atmospheric CO(2) laser to saturate a CO(2) absorption transition at 10.6 mum. Strong excitation by use of a CO(2) laser provides increased signal levels at flame temperatures and simplifies image interpretation. Becau...

In this article the dynamic features of the highly excited vibrational states of the hypochlorous acid (HOCl) non-integrable system are studied using the dynamic potential and Lyapunov exponent approaches. On the condition that the 3:1 resonance between the H-O stretching and H-O-Cl bending modes accompany the 2:1 Fermi resonance between the O-Cl stretching and H-O-Cl bending modes, it is found...