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Title: Robust control of photoassociation of slow O + H collision

Authors:
; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1396858
Grant/Contract Number:
FG02-02ER15344
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Chemical Physics
Additional Journal Information:
Journal Volume: 483-484; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-04 15:47:34; Journal ID: ISSN 0301-0104
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Zhang, Wei, Dong, Daoyi, Petersen, Ian R., and Rabitz, Herschel A.. Robust control of photoassociation of slow O + H collision. Netherlands: N. p., 2017. Web. doi:10.1016/j.chemphys.2016.11.020.
Zhang, Wei, Dong, Daoyi, Petersen, Ian R., & Rabitz, Herschel A.. Robust control of photoassociation of slow O + H collision. Netherlands. doi:10.1016/j.chemphys.2016.11.020.
Zhang, Wei, Dong, Daoyi, Petersen, Ian R., and Rabitz, Herschel A.. Wed . "Robust control of photoassociation of slow O + H collision". Netherlands. doi:10.1016/j.chemphys.2016.11.020.
@article{osti_1396858,
title = {Robust control of photoassociation of slow O + H collision},
author = {Zhang, Wei and Dong, Daoyi and Petersen, Ian R. and Rabitz, Herschel A.},
abstractNote = {},
doi = {10.1016/j.chemphys.2016.11.020},
journal = {Chemical Physics},
number = C,
volume = 483-484,
place = {Netherlands},
year = {Wed Feb 01 00:00:00 EST 2017},
month = {Wed Feb 01 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.chemphys.2016.11.020

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  • In this work, we simulate the laser-induced photoassociation of the collision reaction O+H to generate the OH molecule. The photoassociation process involves the continuum-discrete transition, and the initial wavepacket corresponding to the collision pair is generally given by a superposition of continuum state. By numerically solving the Schroedinger equation with split-operator method, we can take into account implicitly but completely for the continuum state in the photoassociation process. In our simulation, we find interestingly the above threshold dissociation spectrum due to the continuum-continuum transition as well as the target bound states by the photoassociation. In order to analyze the continuummore » state involved, we show the effective method by means of the quasicontinuum state on the Morse potential obtained by numerically diagonalizing the total system.« less
  • The Balmer series emissions from the H(4less than or equal tonless than or equal to10) atoms produced in the reactions of H/sub 2/O, D/sub 2/O, and H/sub 2/S with He/sup m/(2/sup 3/S/sub 1/) were observed by flowing afterglow experiments. The emission intensities were found to be approximately proportional to n/sup -..beta../, where the values of ..beta.. were 2.37 /plus minus/ 0.04 for H/sub 2/O, 2.24 /plus minus/ 0.08 for D/sub 2/O, and 3.39 /plus minus/ 0.05 for H/sub 2/S. These n dependences are different from those of H*(n) produced in the vacuum UV photodissociation and the impact of 100-eV electronsmore » on H/sub 2/O and H/sub 2/S. The n dependences observed in the present study are explained by a model that correlates the parameter ..beta.. to the branching ratio of the precursor Rydberg states of the parent molecule causing (pre)dissociation and autoionization; a larger ..beta.. value implies a higher branching ratio to pre(dissociation) producing H*.« less
  • Laser-induced photoassociation is considered in the framework of the developed quantum-mechanical approach. The analytic formulas for the photoabsorption and photoassociation cross sections are derived. The cases of head-on collisions and high angular momenta of quasi-molecules are analyzed. The expressions for the total cross sections and the energy characteristics of the absorption are obtained. The photoabsorption cross sections corresponding to association of Kr and F atoms in the VUV radiation field of intensity 1 < I < 10{sup 12} W/cm{sup 2} are calculated. The nonlinear translucence of the gaseous medium is revealed in the intensity range 10{sup 6} {approx_lt} I {approx_lt}more » 10{sup 10} W/cm{sup 2}, which is far from saturation. The quantum-mechanical explanation of this effect is given. 19 refs., 2 figs.« less
  • At ambient temperatures, the vapor-phase fluorescence spectrum of the cage amine 1-azabicyclo(2.2.1)heptane (ABCH) shows strong excimer emission (lambda/sub max/ 380 nm), which is widely separated from the structured monomer fluorescence (ca. 256 nm). The ABCH vapor pressure is large enough to allow the quantitative measurement of both monomer and excimer fluorescence decay curves throughout four decades between 298 and 473 K. The photokinetics are examined within the context of a simple monomer/excimer scheme. Below 398 K, monomer decay curves are single exponential, indicating that excimer dissociation is too slow to measure. The temperature dependence of the photokinetic parameters reveals amore » negative temperature coefficient for the formation rate constant (i.e., -10 kJ/mol). On the basis of mean collision diameter of 9 A, the excimer formation probability is ca. 0.12 at 298 K. Above 398 K, the data indicate that excimer dissociation is collisionally induced by ground-state molecules (rate constant 4.5 x 10/sup 8/ M/sup -1/ s/sup -1/ at 423 K). The zero-pressure-extrapolated values of the first-order dissociation rate constants are non-zero and do not show Arrhenius behavior. The temperature and pressure dependence of excimer formation and dissociation is discussed in terms of simple unimolecular rate theory. Data are compared with the binding energy of the ABCH excimer in the condensed phase. The photokinetic data are in general agreement with photostationary measurements carried out at constant ABCH vapor concentration.« less
  • Ab initio configuration interaction (CI) calculations have been performed for the O{sub 2} + H{sub 2} complex in a trapezoidlike collision arrangement with C{sub 2v} symmetry. The potential energy surfaces of the four lowest states of this van der Waals complex (arising from the X{sup 3}{Sigma}{sub g}{sup +} states of the oxygen moiety), as well as the collision-induced b{sup 1}{Sigma}{sub g}{sup +}-a{sup 1}{triangle}g electric dipole transition moment (M{sub b-a}), have been analyzed for different CI expansions, using as a reference determinant the restricted open-shell Hartree-Fock (ROHF) function for the ground state of the complex H{sub 2}(X{sup 1}{Sigma}{sub g}{sup +}) +more » O{sub 2}(X{sup 3}{Sigma}{sub g}{sup -}). The geometry optimized at the ROHF/6-311G level was refined by a partial optimization at the CI level scanning intermolecular distance. The equilibrium distances for the X, a, and b states have been found to be a slightly different in the region 3.02-2.98 A. The larger binding energy of the b{sup 1}{Sigma}{sub g}{sup +} state (2.96 kJ/mol) in comparison with the a{sup 1}{triangle}g (2.1 kJ/mol) and ground X{sup 3}{Sigma}{sub g}{sup -} states (1.35 kJ/mol) presumably could be explained as resulting from charge-transfer interactions. A good convergence of the calculated transition moment M{sub b-a} for the larger CI expansions (approximately 50,000 configuration-state functions) has been obtained. The calculated collision-induced intensity of the b{sup 1}{Sigma}{sub g}{sup +} - a{sup 1}{triangle}g and a{sup 1}{triangle}g - X{sup 3}{Sigma}{sub g}{sup -} transitions in molecular oxygen are in reasonable agreement with recent experimental data for several foreign gases.« less