Search results for "PolyAT"
showing 10 items of 53 documents
Rotational Transitions of CO+Induced by Atomic Hydrogen
2008
The CO+ molecular ion has been observed in photon-dominated regions. Recent modeling has not been able to explain the abundances of CO+ in these regions. The most abundant collision partners are believed to be hydrogen atoms, hydrogen molecules, and electrons. The reactions of these species with CO+ have been studied previously and found to be fast. The only inelastic processes studied before were collisions of CO+ with electrons. Here we investigate the inelastic collisions of CO+ with hydrogen atoms. We argue that this can be done on the lowest triplet electronic state. This implies that CO+ ions, in a hydrogen atom dominated surrounding, experiences a few inelastic collisions before reac…
Electron and nuclear dynamics of a molecular ion in an intense laser field
2004
The dynamics of a two-dimensional $\mathrm{H}_{2}^{+}$ molecule interacting with a strong laser pulse beyond the usual approximation of fixed nuclei is presented. The motion of the nuclei is studied by using the classical Newton laws while the electron is described with a full quantal treatment. The axis of the molecule, initially not aligned to the laser field, performs a long-period pendular motion around the laser polarization axis. Vibrational degrees of freedom are seen to be excited. The radiation emitted by the oscillating charges presents variations that are synchronous to the pendular motion. The possibility of monitoring the motion of the molecule through the emitted radiation is …
β-decay of22O
2005
A mass-separated 12 C 22 O molecular ion beam from the ISOLDE facility was used to study the decay of neutron-rich 22 O. The experimental results were compared with the results from an earlier experiment and predictions by shellmodel calculations using various effective interactions. The mechanism leading to the vanishing decay strength to the first 1 + level of the 22 F nucleus, predicted with the USD effective interaction but not supported by the experimental data, is analysed.
Study of resonance interactions in polyatomic molecules on the basis of highly accurate experimental data: Set of strongly interacting Bands ν10(B1),…
2016
Abstract The highly accurate (experimental accuracy in line positions ~ ( 1 − 3 ) × 10 − 4 cm − 1 ) FTIR ro-vibrational spectra of CH2=CD2 in the region of 600–1300 cm−1, where the fundamental bands ν10, ν7, ν4, ν8, ν3, and ν6 are located, were recorded and analyzed with the Hamiltonian model which takes into account resonance interactions between all six studied bands. About 12 200 ro-vibrational transitions belonging to these bands (that is considerably more than it was made in the preceding studies for the bands ν10, ν7, ν8, ν3 and ν6; transitions belonging to the ν4 band were assigned for the first time) were assigned in the experimental spectra with the maximum values of quantum number…
Ionization dynamics of a model molecular ion
2005
We study the ionization dynamics of a model one-dimensional molecular ion as a function of the internuclear distance R, for different values of the laser intensity. The electron–nucleus potential is assumed to be a Poschl–Teller potential, whose parameters are chosen to have only two bare bound molecular states in the range of R considered. We describe three different theoretical approaches to study the dynamics of the system: an exact numerical, a semiperturbative and a phenomenological approach. All these approaches indicate the presence of a sharp ionization peak for a critical value of the internuclear distance, for which the energy difference between the two bound levels coincides with…
Model-independent determination of dissociation energies: method and applications
2003
A number of methods are available for the purpose of extracting dissociation energies of polyatomic particles. Many of these techniques relate the rate of disintegration at a known excitation energy to the value of the dissociation energy. However, such a determination is susceptible to systematic uncertainties, mainly due to the unknown thermal properties of the particles and the potential existence of 'dark' channels, such as radiative cooling. These problems can be avoided with a recently developed procedure, which applies energy-dependent reactions of the decay products as an uncalibrated thermometer. Thus, it allows a direct measurement of dissociation energies, without any assumption …
The Study Of The Nuclear Motion In D2+ Molecular Ion By Using The Harmonic Spectra
2007
In this paper we show how it is possible to investigate the nuclei dynamics of a D2+ molecular ion by using the high harmonic generation spectra emitted by the system when subjected to an intense laser field. In particular, the emitted spectra contains, in addition to the usual odd harmonic peaks, additional satellite peaks whose frequency spacing is equal to the vibrational frequency of the nuclei.
The local group K(4) in the algebraic approach to vibrational spectra of tetrahedral molecules: Application to silane
1992
Abstract In a previous paper, Michelot and Moret-Bailly (J. Phys., 48, 51 (1987)) proposed an algebraic treatment of vibrational stretching modes in polyatomic molecules. They used the properties of the group chain U(p + 1) ⊃ U(p) ⊃ S(p) ⊃ G for the study of p identical oscillators. The molecule, with p equivalent bonds described as a system of p oscillators, has a symmetry group G. We develop in this paper an application to p = 4 equivalent oscillators. We show that, for a tetrahedral molecule, the group chain U(5) ⊃ U(4) ⊃ S(4) ≈ Td can be completed, in a local point of view, with a particular group K(4): U(5) ⊃ U(4) ⊃ K(4) ⊃ S(4) ≈ T d This group provides us with available labels which c…
The Controversy Between Erich Hückel and Linus Pauling over the Benzene Problem
2009
Shortly after Huckel’s quantum-theoretical work on the problem of aromatic compounds was published, the first paper on the same subject by the American Linus Pauling also appeared. It was the fifth installment of a total of seven that Pauling published between April 1931 and July 1933 under the general title The Nature of the Chemical Bond.This fifth part was the first coauthored with his pupil George Wheland, a National Research Fellow in Pasadena. In their quantum mechanical treatment of benzene, naphthaline and free organic radicals, they applied a “VB” approximation slightly different from Huckel’s “first method” yet sharing some resemblance with it. The two subsequent parts of Pauling’…
A Comparative Study of Poly(Azure A) Film-Modified Disposable Electrodes for Electrocatalytic Oxidation of H₂O₂: Effect of Doping Anion.
2018
In the present paper, poly(azure A) (PAA) films were electrosynthetized in the presence of different doping anions on disposable screen-printed carbon electrodes (SPCEs). The anions used included inorganic monoatomic (chloride and fluoride), inorganic polyatomic (nitrate and sulfate) and organic polyatomic (dodecyl sulfate, DS) species. The coated electrodes thus obtained were characterized by electrochemical techniques and SEM. They showed improved electrocatalytic activities towards hydrogen peroxide oxidation compared to that of a bare SPCE. In particular, the insertion of DS anions inside PAA films provided a special sensitivity to the electrocatalysis of H2O2, which endowed these elect…