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Journal articles on the topic 'Molecular collision theory'

Author: Grafiati

Published: 4 June 2021

Last updated: 15 February 2022

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1

Halonen, Roope, Evgeni Zapadinsky, Theo Kurtén, Hanna Vehkamäki, and Bernhard Reischl. "Rate enhancement in collisions of sulfuric acid molecules due to long-range intermolecular forces." Atmospheric Chemistry and Physics 19, no. 21 (October 30, 2019): 13355–66. http://dx.doi.org/10.5194/acp-19-13355-2019.

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Abstract. Collisions of molecules and clusters play a key role in determining the rate of atmospheric new particle formation and growth. Traditionally the statistics of these collisions are taken from kinetic gas theory assuming spherical noninteracting particles, which may significantly underestimate the collision coefficients for most atmospherically relevant molecules. Such systematic errors in predicted new particle formation rates will also affect large-scale climate models. We studied the statistics of collisions of sulfuric acid molecules in a vacuum using atomistic molecular dynamics simulations. We found that the effective collision cross section of the H2SO4 molecule, as described by an optimized potentials for liquid simulation (OPLS). OPLS all-atom force field, is significantly larger than the hard-sphere diameter assigned to the molecule based on the liquid density of sulfuric acid. As a consequence, the actual collision coefficient is enhanced by a factor of 2.2 at 300 K compared with kinetic gas theory. This enhancement factor obtained from atomistic simulation is consistent with the discrepancy observed between experimental formation rates of clusters containing sulfuric acid and calculated formation rates using hard-sphere kinetics. We find reasonable agreement with an enhancement factor calculated from the Langevin model of capture, based on the attractive part of the atomistic intermolecular potential of mean force.

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Басалаев, А. А., А. Г. Бузыкин, В. В. Кузьмичев, М. Н. Панов, А. В. Петров, and О. В. Смирнов. "Взаимодействие alpha-частиц keV-энергий с молекулами глицил-лейцина." Письма в журнал технической физики 47, no. 12 (2021): 23. http://dx.doi.org/10.21883/pjtf.2021.12.51062.18746.

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Radiation damage to isolated glycyl-leucine (C8H16N2O3) molecules caused by interaction with He2+ ions was studied. For the first time, the relative cross sections of the main processes of changes in the charge state of the collision partners and the relative cross sections of the fragmentation processes of singly and doubly charged molecular ions formed during single collisions of glycyl-leucine molecules with ions have been obtained. The optimized geometry of the molecule and singly charged glycyl-leucine ion was calculated using the density functional theory (DFT).

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3

Sun, Zhong-Fa, Marc C. van Hemert, Jérôme Loreau, Ad van der Avoird, Arthur G. Suits, and David H. Parker. "Molecular square dancing in CO-CO collisions." Science 369, no. 6501 (July 16, 2020): 307–9. http://dx.doi.org/10.1126/science.aan2729.

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Knowledge of rotational energy transfer (RET) involving carbon monoxide (CO) molecules is crucial for the interpretation of astrophysical data. As of now, our nearly perfect understanding of atom-molecule scattering shows that RET usually occurs by only a simple “bump” between partners. To advance molecular dynamics to the next step in complexity, we studied molecule-molecule scattering in great detail for collision between two CO molecules. Using advanced imaging methods and quasi-classical and fully quantum theory, we found that a synchronous movement can occur during CO-CO collisions, whereby a bump is followed by a move similar to a “do-si-do” in square dancing. This resulted in little angular deflection but high RET to both partners, a very unusual combination. The associated conditions suggest that this process can occur in other molecule-molecule systems.

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4

Abel, Martin, Lothar Frommhold, Xiaoping Li, and K. L. C. Hunt. "Comparison of the Calculated Collision-Induced Absorption Spectra by Dense Hydrogen-Helium, Deuterium-Helium, and Tritium-Helium Gas Mixtures." Journal of Atomic, Molecular, and Optical Physics 2011 (October 11, 2011): 1–3. http://dx.doi.org/10.1155/2011/470530.

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We have recently determined the induced dipole surface (IDS) and potential energy surface (PES) of collisional H2-He complexes. We have used these surfaces to compute the binary collision-induced absorption spectra of H2 molecules interacting with He atoms and of D2 molecules interacting with He atoms. Here we extend these calculations to the case of T2 molecules interacting with He atoms. Whereas the electronic structure of X2-He is virtually the same for all hydrogen isotopes X = H, D, or T, the collisional dynamics and molecular scattering wave functions are different for the different collisional pairs. We have calculated spectra up to a temperature of 9000 K and frequencies up to 20,000 cm−1. Here we compare the calculated collision-induced absorption spectra for the different hydrogen isotopes. While we have observed reasonable agreement between our calculations and laboratory measurements for the collisional H2-He and D2-He complexes, there are no laboratory measurements for T2-He collisional complexes, and one must rely on the fundamental theory, supported by the agreement between theory and experiment for the other isotopes.

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5

Tao, Yi, Zhongwu Li, Quan Han, Chengdong Sun, Yan Zhang, and Yunfei Chen. "Theory of aerodynamic heating from molecular collision analysis." Physics Letters A 384, no. 4 (February 2020): 126098. http://dx.doi.org/10.1016/j.physleta.2019.126098.

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6

Abel, Martin, and Lothar Frommhold. "Collision-induced spectra and current astronomical research." Canadian Journal of Physics 91, no. 11 (November 2013): 857–69. http://dx.doi.org/10.1139/cjp-2012-0532.

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Collision-induced spectra are the spectra of complexes of two or more atoms or molecules in a “fly-by” collisional encounter. Collision-induced absorption (CIA) has been observed in many dense gases and gas mixtures, in most cases at infrared frequencies in the form of quasi continua, and also in liquids and solids. CIA spectra of several binary complexes have been computed using modern quantum chemical methods, combined with molecular scattering theory, which couples the collisional complex to the radiation field as usual in other spectroscopic work. Binary collisional systems, such as H2 interacting with another H2 molecule, or with a helium or hydrogen atom, are first candidates for such computational work, owing to their small number of electrons and the astrophysical interest in such systems. The computed CIA spectra are found to be in close agreement with existing laboratory measurements of such spectra. Laboratory measurements exist at a limited selection of temperatures around 300 K and lower, but theory currently also provides CIA data for temperatures up to 9000 K and for higher frequencies (well into the visible), on a dense grid of temperatures and frequencies. For such calculations, detailed potential energy surfaces (PES) of the supermolecular complexes, along with the induced dipole surfaces (IDS), are needed so that the rotovibrational matrix elements of PES and IDS may be computed for the molecules involved, which may be highly rotovibrationally excited. Modern astronomical research needs opacity tables for analyses of the atmospheres of “cool” objects, such as cool white dwarfs, solar and extrasolar planets and their big moons, cool main sequence stars, and “first” stars, which are briefly described in a concluding section.

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7

Van-Thanh, Nguyen, and I. Rossi. "Far-infrared collision-induced absorption in compressed gaseous polar linear molecules: application to N2O." Canadian Journal of Physics 66, no. 1 (January 1, 1988): 7–10. http://dx.doi.org/10.1139/p88-002.

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This paper deals with computations of the far-infrared collision-induced absorptions for polar linear molecules. We have considered Frost's theory for dipole- and quadrupole-induced dipole absorptions in bimolecular collisions, taking the anisotropy of the molecular polarizability into account. In addition to the induced rotational interaction, a translational effect may not be negligible. Detailed expressions for different contributions to the integrated intensities are reported for N2O. Using these calculated expressions and the moderately low pressure data, we have deduced a value for the quadrupole moment of N2O, [Formula: see text].

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8

Padkjér, Søren Berg, and Jan Linderberg. "Electronic hamiltonians for collision theory." International Journal of Quantum Chemistry 36, S23 (June 19, 2009): 1–15. http://dx.doi.org/10.1002/qua.560360804.

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9

Anisimova, I. V., and A. V. Ignat'ev. "On the Theory of Determining the Transport Characteristics of Gas Mixtures." Materials Science Forum 992 (May 2020): 823–27. http://dx.doi.org/10.4028/www.scientific.net/msf.992.823.

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The paper considers the identification of properties of real gases and creation of nanomaterials on the basis of molecular and kinetic theory of gases, namely the Boltzmann equation. The collision term of the Boltzmann equation is used in the algorithm for the identification of transport properties of media. The article analyses the uniform convergence of improper integrals in the collision term of the Boltzmann equation depending on the conditions for the connection between the kinetic and potential energy of interacting molecules. This analysis allows to soundly identify the transport coefficient in macro equations of heat and mass transfer.

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10

Van-Thanh, Nguyen, and I. Rossi. "Far-infrared collision-induced absorption in some compressed gaseous halogenated methanes." Canadian Journal of Physics 63, no. 4 (April 1, 1985): 475–78. http://dx.doi.org/10.1139/p85-074.

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Calculations of the collision-induced rotational and translational absorptions have been performed for seven pure halogenated methanes CH3F, CH3Cl, CF3H, CF3Cl, CF3Br, CCl3H, and CCl3F. We have considered the theory of Frost for multipole-induced dipolar absorption in bimolecular collisions taking the anisotropy of the molecular polarizability into account. The comparison with experimental literature data of CF3H and CF3Cl was reported; a reasonable agreement was obtained only for CF3Cl.

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11

Swanson, David C. "Quantitative ion mobility spectroscopy based on molecular collision rate theory." International Journal for Ion Mobility Spectrometry 16, no. 4 (May 31, 2013): 265–74. http://dx.doi.org/10.1007/s12127-013-0134-4.

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12

Joslin, C. G. "Collision-induced absorption in the fundamental band of nitrogen gas." Canadian Journal of Physics 65, no. 12 (December 1, 1987): 1629–35. http://dx.doi.org/10.1139/p87-268.

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Compressed nitrogen gas absorbs weakly in the vicinity of its vibrational fundamental frequency (ωvib = 2330 cm−1), with an intensity proportional to the square of the density. This absorption arises through vibrational modulation of the quadrupole-induced collisional dipole moment of a pair of N2 molecules. By neglecting the small anisotropy in the N2 intermolecular potential, we represent the spectral profile as the convolution of a single-molecule vibration–rotation band with a two-molecule translational component. Information theory is used to estimate the "least biased" form for the latter, based on our knowledge of its first four nonvanishing spectral moments. Our theory contains no adjustable parameters, yet yields results in good agreement with experiment. Our analysis shows that the anisotropic component of the molecular polarizability makes a fairly substantial contribution, about 12%, to the spectral intensity.

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13

Chatzidimitriou-Dreismann, C. Aris. "Maxwell’s Demon Observing Creation of a Molecular Vibration." Zeitschrift für Naturforschung A 69, no. 7 (July 1, 2014): 287–96. http://dx.doi.org/10.5560/zna.2014-0005.

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Quantum correlations and associated quantum information concepts (e. g. quantum discord, entanglement, quantum Maxwell’s demon) provide novel insights in various quantum-information processing tasks, quantum-thermodynamics processes, open-system dynamics, quantum molecular dynamics, and general many-body physics. We investigate a new effect of correlations accompanying collision of two quantum systems A and B, the latter being part of a larger (interacting) system B+D. In contrast to the usual case of a classical ‘environment’ or ‘demon’ (which can have only classical correlations with A+B during and after the collision), the quantum case exhibits striking new features. Here, in the frame of incoherent inelastic neutron scattering (INS) and vibrational dynamics of molecules, we report experimental evidence of a new phenomenon: quantum deficit of momentum transfer in an elementary neutron-molecule collision, in particular, in INS from single H2O molecules confined in channels with sub-nanometer diameter. The INS findings are in clear contrast to conventional theoretical expectations, but are naturally (albeit qualitative) interpreted in the frame of modern theory of quantumness of correlations, thus also proposing a new operational meaning of quantum discord and related measures.

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14

Valiente, Manuel, and Nikolaj Thomas Zinner. "Quantum collision theory in flat bands." Journal of Physics B: Atomic, Molecular and Optical Physics 50, no. 6 (March 7, 2017): 064004. http://dx.doi.org/10.1088/1361-6455/aa60de.

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15

Eno, Larry. "Wavefunction sensitivity in quantum collision theory." Molecular Physics 83, no. 1 (September 1994): 137–43. http://dx.doi.org/10.1080/00268979400101131.

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16

Dong, Yan Hua, and Xiao Jia Li. "Ab Initio Molecular Dynamics Simulations on High-Temperature Reaction Rates of Reactions KO+CO==K+CO₂, KO+C=K+CO, and K₂O+CO₂==K₂CO₃." Advanced Materials Research 875-877 (February 2014): 1037–41. http://dx.doi.org/10.4028/www.scientific.net/amr.875-877.1037.

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In this paper, we present a novel approach for calculating chemical reaction rates based on molecular collision theory, in which molecular collision cross sections are calculated by averaging over all reactive trajectories from ab initio molecular dynamics simulations. The molecular collision radius is determined by both reactive and non-reactive trajectories of molecular dynamics under constant temperature. Thus, both steric and temperature effects have been take into account for molecular collision cross sections. We have applied this approach to calculate reaction rates of reactions KO+CO==K+CO2, KO+C==K+CO, and K2O+CO2==K2CO3 under high temperature. It also shows that under higher temperature, the probabilities of a successful reaction resulting from particle collision are low, because the products are not stable.

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17

Ter Meulen, J. J. "Inelastic collisions of interstellar molecules." Symposium - International Astronomical Union 178 (1997): 241–52. http://dx.doi.org/10.1017/s0074180900009396.

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The rotational energy transfer of NH3, OH and D2CO in inelastic collisions with He and H2 is studied in a crossed molecular beam experiment. The molecules are prepared in a single initial state by rotational cooling in an adiabatic expansion followed by electrostatic state selection. Relative state-to-state cross sections are determined by measuring the collision induced redistribution of the population of the initial state by using state selective laser detection techniques. The results for NH3 and OH are compared to theoretical values obtained from quantum calculations. Except for NH3 — He where theory predicts a parity selection rule for transitions to the 33 and 43 states, which is not observed in the experiment, good agreement between experiment and theory is obtained.

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18

Girardeau, M. D. "Theory of half-collision cross sections." International Journal of Quantum Chemistry 29, no. 5 (May 1986): 1483–92. http://dx.doi.org/10.1002/qua.560290539.

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19

Zygelman, B., A. Dalgarno, and R. D. Sharma. "Molecular theory of collision-induced fine-structure transitions in atomic oxygen." Physical Review A 49, no. 4 (April 1, 1994): 2587–606. http://dx.doi.org/10.1103/physreva.49.2587.

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20

Madsen, Dane K., Yiwen Xiao, and Larry Eno. "Multimode Floquet theory for atomic and molecular laser‐modified collision processes." Journal of Chemical Physics 104, no. 4 (January 22, 1996): 1344–49. http://dx.doi.org/10.1063/1.470791.

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21

Matúška, Ján. "An efficient and accurate method to calculate diffusion coefficient of structured particles. A first case study of Pb diffusion in rare gases." Acta Chimica Slovaca 9, no. 2 (October 1, 2016): 158–62. http://dx.doi.org/10.1515/acs-2016-0027.

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Abstract Diffusion coefficient depends on temperature, pressure, reduced mass of colliding particles and collision cross section. The presented method is designed to calculate the diffusion coefficient in loose systems containing molecules with relatively complicated colliding trajectories. It is a combination of the Chapman-Enskog theory and the molecular dynamics calculation. The Chapman-Enskog theory provides the relation between the diffusion coefficient and the collision cross section which is the result of multiple integration of the scattering angle of all possible initial conditions of the collision. The scattering angle is obtained by numerical integration of the Newton’s equation of motion with previously selected initial conditions. The proposed method has been verified for the simple system of a lead atom diffusion in rare gases and the results were compared to those of two other theoretical methods.

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22

Dash, J. G., and J. S. Wettlaufer. "The surface physics of ice in thunderstorms." Canadian Journal of Physics 81, no. 1-2 (January 1, 2003): 201–7. http://dx.doi.org/10.1139/p03-011.

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Laboratory and field studies have shown that thunderstorm electrification is principally due to rebounding collisions between ice particles and hail. Recent studies have provided clues for an understanding of the microphysics of the charging mechanism, involving the dynamics of vapor growth, molecular diffusion, and collisionally modified surface melting. The theory is in quantitative agreement with the systematic dependence of charge and mass transfer on growth rate, collision speed, and temperature. PACS Nos.: 05.70-a, 64.10+h, 64.70-p, 63.35

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23

Xia, Zonghuang, Demin Wang, and Shigang Wu. "INVESTIGATION OF VACANCY DISTRIBUTION IN C+−B, C+−N, C+−Be andC+−O ION-ATOM COLLISIONS." International Journal of PIXE 06, no. 01n02 (January 1996): 65–69. http://dx.doi.org/10.1142/s0129083596000089.

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The mechanism of vacancy distribution in C +− B , C +− N , C +− Be , and C +− O ion-atom collision process is studied in this paper based on molecular orbital theory. It translates intensity ratio of X-ray and Auger decay in ion-atom collision process.

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24

Xiong, Xiao-he, Yan-jun Ding, Shuo Shi, and Zhi-min Peng. "Shock Tube Measurement of Ethylene Ignition Delay Time and Molecular Collision Theory Analysis." Chinese Journal of Chemical Physics 29, no. 6 (December 27, 2016): 761–66. http://dx.doi.org/10.1063/1674-0068/29/cjcp1605104.

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25

Cercignani, C. "Collision models in classical and relativistic kinetic theory." Il Nuovo Cimento A 87, no. 2 (May 1985): 96–108. http://dx.doi.org/10.1007/bf02902337.

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26

Moulane, Y., J. Zs Mezei, V. Laporta, E. Jehin, Z. Benkhaldoun, and I. F. Schneider. "Reactive collision of electrons with CO+ in cometary coma." Astronomy & Astrophysics 615 (July 2018): A53. http://dx.doi.org/10.1051/0004-6361/201832912.

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Context. In order to improve our understanding of the kinetics of the cometary coma, theoretical studies of the major reactive collisions in these environments are needed. Deep in the collisional coma, inelastic collisions between thermal electrons and molecular ions result in recombination and vibrational excitation, the rates of these processes being particularly elevated due to the high charged particle densities in the inner region. Aims. This work addresses the dissociative recombination, vibrational excitation, and vibrational de-excitation of electrons with CO+ molecular cations. The aim of this study is to understand the importance of these reactive collisions in producing carbon and oxygen atoms in cometary activity. Methods. The cross-section calculations were based on multichannel quantum defect theory. The molecular data sets, used here to take into account the nuclear dynamics, were based on ab initio R-matrix approach. Results. The cross-sections for the dissociative recombination, vibrational excitation, and vibrational de-excitation processes, for the six lowest vibrational levels of CO+ – relevant for the electronic temperatures observed in comets – are computed, as well as their corresponding Maxwell rate coefficients. Moreover, final state distributions for different dissociation pathways are presented. Conclusions. Among all reactive collisions taking place between low-energy electrons and CO+, the dissociative recombination is the most important process at electronic temperatures characterizing the comets. We have shown that this process can be a major source of O(3P), O(1D), O(1S), C(3P) and C(1D) produced in the cometary coma at small cometocentric distances.

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27

Joachain, C. J. "Laser-Assisted Electron-Atom Collisions." Laser Chemistry 11, no. 3-4 (January 1, 1991): 273–77. http://dx.doi.org/10.1155/lc.11.273.

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The theoretical methods which have been developed to analyze laser-assisted electron-atom collisions are reviewed. Firstly, the scattering of an electron by a potential in the presence of a laser field is considered. The analysis is then generalized to laser-assisted collisions of electrons with “real” atoms having an internal structure. Two methods are discussed: a semi-perturbative approach suitable for fast incident electrons and a fully non-perturbative theory—the R-matrix-Floquet method—which is applicable to the case of slow incident electrons. In particular it is shown how the dressing of the atomic states by the laser field can affect the collision cross sections.

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Kazansky, A. K., and V. N. Ostrovsky. "Rydberg-atom - ion collision: classical theory of intrashell transitions." Journal of Physics B: Atomic, Molecular and Optical Physics 29, no. 16 (August 28, 1996): 3651–72. http://dx.doi.org/10.1088/0953-4075/29/16/012.

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29

Tulkki, J., G. B. Armen, T. �berg, B. Crasemann, and M. H. Chen. "Quantum theory of post-collision interaction in inner-shell photoionization." Zeitschrift f�r Physik D Atoms, Molecules and Clusters 5, no. 3 (September 1987): 241–52. http://dx.doi.org/10.1007/bf01436929.

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30

Zhang, Qian, Gerard Leng, and Vengatesan Govindaraju. "Duration of collision-free motion of unmanned vehicles in a confined area." Robotica 34, no. 2 (June 13, 2014): 347–60. http://dx.doi.org/10.1017/s0263574714001489.

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SUMMARYThis paper provides a mathematical approach to study the duration of collision-free motion of multiple unmanned autonomous vehicles (UXVs) operating in confined areas. A simple geometric model of the UXVs is first proposed, and the dynamics of the model is shown. The expected time of first collision is then formulated using the concept of mean free path from molecular dynamics. Monte-Carlo simulation is performed to verify the theory developed. The expected time of first collision is a function of the number of UXVs, the UXV speed and the sensor field of view (FOV) for a given operational area and vehicle size. Furthermore, the critical number of UXVs, above which collision can be deemed to occur instantly, is obtained.

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BÖYÜKATA, MUSTAFA, ZİYA B. GÜVENÇ, SULEYMAN ÖZÇELİK, PERİHAN DURMUŞ, and JULIUS JELLINEK. "REACTION DYNAMICS OF Nin (n =19 and 20) WITH D2: DEPENDENCE ON CLUSTER SIZE, TEMPERATURE AND INITIAL ROVIBRATIONAL STATES OF THE MOLECULE." International Journal of Modern Physics C 16, no. 02 (February 2005): 295–308. http://dx.doi.org/10.1142/s0129183105007108.

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The Ni n (n =19, 20) + D 2 (v, j) collision systems have been studied to investigate the dependence of cluster reactivity on the cluster temperature and the initial rovibrational states of the molecule using quasiclassical molecular dynamics simulations. The clusters are described by an embedded atom potential, whereas the interaction between the molecule and the cluster is modeled by a LEPS (London–Eyring–Polani–Sato) potential energy function. Reaction (dissociative adsorption) cross-sections are computed as functions of the collision energy for different initial rovibrational states of the molecule and for different temperatures of the clusters. Rovibrational, temperature and size-dependent rate constants are also presented, and the results are compared with earlier studies. Initial vibrational excitation of the molecule increases the reaction cross-section more efficiently than the initial rotational excitation. The reaction cross-sections strongly depend on the collision energies below 0.1 eV .

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Connor, J. N. L., and W. J. E. Southall. "An improved Bessel uniform approximation of non-integer order for use in semiclassical collision theory: application to vibrationally inelastic molecular collisions." Journal of Physical Chemistry 90, no. 16 (July 1986): 3599–603. http://dx.doi.org/10.1021/j100407a027.

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Hopersky, A. N., and V. V. Chuvenkov. "Non-perturbative quantum theory of the post-collision interaction effect." Journal of Physics B: Atomic, Molecular and Optical Physics 36, no. 14 (June 27, 2003): 2987–90. http://dx.doi.org/10.1088/0953-4075/36/14/302.

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Dagg, I. R., A. Anderson, W. Smith, P. J. Reid, C. G. Joslin, and C. G. Gray. "Collision-induced absorption in cyclopropane (C3H6)." Canadian Journal of Physics 70, no. 2-3 (February 1, 1992): 134–39. http://dx.doi.org/10.1139/p92-017.

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We have measured the far-infrared absorption spectrum of cylopropane (C3H6) at frequencies up to 400 cm−1, at densities up to 5 amagat at 295 K and up to 16 amagat at 360 K, using a combination of Fourier-transform and laser techniques. (An amagat is defined as the density of a gas at N.T.P.). By studying the density-dependence of absorption, we have isolated the collisional component of the spectrum. This arises from pair dipole moments induced by the permanent quadrupole, octopole, and hexadecapole moments of the C3H6 molecule. To the extent that the intermolecular potential is isotropic, the induced spectrum can be expressed as the convolution of symmetric top free rotation spectra with translational spectra representing the relative motion of an interacting molecular pair. The former are calculated using expressions recently derived. For the latter we use information theory to provide a "least-biased" estimate based only on available information concerning the zeroth and second moments of the translational frequency spectrum, which can be calculated without approximation within the framework of equilibrium statistical mechanics. The result of these computations is a simple analytic expression for the absorption coefficient [Formula: see text], which is entirely free of adjustable parameters, and yet yields a good representation of the experimental results over most of the frequency range. Our results lend strong support to the theoretical values of the multipole moments calculated by other workers.

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35

Minaev, Boris. "Photochemistry and Spectroscopy of Singlet Oxygen in Solvents. Recent Advances which Support the Old Theory." Chemistry & Chemical Technology 10, no. 4s (December 25, 2016): 519–30. http://dx.doi.org/10.23939/chcht10.04si.519.

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Molecular oxygen is a paramagnetic gas with the triplet O2( ) ground state which exhibits just sluggish chemical reactivity in the absence of radical sources. In contrast, the excited metastable singlet oxygen O2( ) is highly reactive; it can oxygenate organic molecules in a wide range of specific reactions which differ from those of the usual triplet oxygen of the air. This makes the singlet oxygen an attractive reagent for new synthesis and even for medical treatments in photodynamic therapy. As an important intermediate O2( ) has attracted great attention of chemists during half-century studies of its reactivity and spectroscopy, but unusual properties of singlet oxygen makes it difficult to unravel all mysterious features. The semiempirical theory of spin-orbit coupling in dioxygen and in collision complexes of O2 with diamagnetic molecules proposed in 1982 year has explained and predicted many photochemical and spectral properties of dioxygen produced by the dye sensitization in solvents. Recent experiments with direct laser excitation of O2 in solvents provide a complete support of the old theory. The present review scrutinizes the whole story of development and experimental verification of this theory.

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36

Kocbach, Ladislav. "Computer graphics based analysis and visualization of semiclassical collision theory." Physica Scripta T46 (January 1, 1993): 261–65. http://dx.doi.org/10.1088/0031-8949/1993/t46/041.

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37

ATİŞ, MURAT, CEM ÖZDOĞAN, and ZİYA B. GÜVENÇ. "PARALLELIZATION OF A MOLECULAR DYNAMICS SIMULATION OF AN ION-SURFACE COLLISION SYSTEM: Ar–Ni(100)." International Journal of Modern Physics C 16, no. 06 (June 2005): 969–90. http://dx.doi.org/10.1142/s0129183105007649.

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Parallel molecular dynamics simulation study of the ion-surface collision system is reported. A sequential molecular dynamics simulation program is converted into a parallel code utilizing the concept of parallel virtual machine (PVM). An effective and favorable algorithm is developed. Our parallelization of the algorithm shows that it is more efficient because of the optimal pair listing, linear scaling, and constant behavior of the internode communications. The code is tested in a distributed memory system consisting of a cluster of eight PCs that run under Linux (Debian 2.4.20 kernel). Our results on the collision system are discussed based on the speed up, efficiency and the system size. Furthermore, the code is used for a full simulation of the Ar–Ni (100) collision system and calculated physical quantities are presented.

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Santhi, N., PL Sabarathinam, M. Emayavaramban C. Gopi, and C. Manivannan. "Molecular Interaction Studies in Binary Liquid Mixtures from Ultrasonic Data." E-Journal of Chemistry 7, no. 2 (2010): 648–54. http://dx.doi.org/10.1155/2010/487874.

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Ultrasonic velocities and densities of the binary liquid mixtures of dimethy1 sulphoxide (DMSO) with phenol,o-cresol,m-cresol,p-cresol andp-chlorophenol at 318.15 K, over the entire composition range were measured. The theoretical values of ultrasonic velocity were evaluated using the Nomoto’s Relation (NR), Ideal Mixture Relation (IMR), Free Length Theory (FT) and Collision Factor Theory (FLT). The validity of these relations and theories was tested by comparing the computed sound velocities with experimental values. Further, the molecular interaction parameter (α) was computed by using the experimental and the theoretical ultrasonic velocity values. The variation of this parameter with composition of the mixtures has been discussed in terms of molecular interaction in these mixtures.

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BANASIAK, JACEK, GIOVANNI FROSALI, and GIAMPIERO SPIGA. "ASYMPTOTIC ANALYSIS FOR A PARTICLE TRANSPORT EQUATION WITH INELASTIC SCATTERING IN EXTENDED KINETIC THEORY." Mathematical Models and Methods in Applied Sciences 08, no. 05 (August 1998): 851–74. http://dx.doi.org/10.1142/s021820259800038x.

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In this paper we perform the asymptotic analysis for a linear transport equation for test particles in an absorbing and inelastically scattering background, when the excited species can be considered as non-participating. This model is derived in the frame of extended kinetic theory and rescaled with the Knudsen number ∊. After examining the main properties of the collision model and of the scattering operator in the case with an infinite interval of energy as well as the case with a finite interval, the modified (compressed) Chapman–Enskog expansion procedure is applied to find the asymptotic equation for small mean free path. A specific feature of this model is that the collision operator has an infinite-dimensional null-space. The main result is that in the small mean free path approximation on [Formula: see text] level we obtain a free molecular flow for a suitable hydrodynamic quantity, rather than the diffusion which is typical for linear transport problems.

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40

Wu, Lei, Craig White, Thomas J. Scanlon, Jason M. Reese, and Yonghao Zhang. "A kinetic model of the Boltzmann equation for non-vibrating polyatomic gases." Journal of Fluid Mechanics 763 (December 9, 2014): 24–50. http://dx.doi.org/10.1017/jfm.2014.632.

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AbstractA kinetic model of the Boltzmann equation for non-vibrating polyatomic gases is proposed, based on the Rykov model for diatomic gases. We adopt two velocity distribution functions (VDFs) to describe the system state; inelastic collisions are the same as in the Rykov model, but elastic collisions are modelled by the Boltzmann collision operator (BCO) for monatomic gases, so that the overall kinetic model equation reduces to the Boltzmann equation for monatomic gases in the limit of no translational–rotational energy exchange. The free parameters in the model are determined by comparing the transport coefficients, obtained by a Chapman–Enskog expansion, to values from experiment and kinetic theory. The kinetic model equations are solved numerically using the fast spectral method for elastic collision operators and the discrete velocity method for inelastic ones. The numerical results for normal shock waves and planar Fourier/Couette flows are in good agreement with both conventional direct simulation Monte Carlo (DSMC) results and experimental data. Poiseuille and thermal creep flows of polyatomic gases between two parallel plates are also investigated. Finally, we find that the spectra of both spontaneous and coherent Rayleigh–Brillouin scattering (RBS) compare well with DSMC results, and the computational speed of our model is approximately 300 times faster. Compared to the Rykov model, our model greatly improves prediction accuracy, and reveals the significant influence of molecular models. For coherent RBS, we find that the Rykov model could overpredict the bulk viscosity by a factor of two.

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de la Lande, Aurélien, Aurelio Alvarez-Ibarra, Karim Hasnaoui, Fabien Cailliez, Xiaojing Wu, Tzonka Mineva, Jérôme Cuny, et al. "Molecular Simulations with in-deMon2k QM/MM, a Tutorial-Review." Molecules 24, no. 9 (April 26, 2019): 1653. http://dx.doi.org/10.3390/molecules24091653.

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deMon2k is a readily available program specialized in Density Functional Theory (DFT) simulations within the framework of Auxiliary DFT. This article is intended as a tutorial-review of the capabilities of the program for molecular simulations involving ground and excited electronic states. The program implements an additive QM/MM (quantum mechanics/molecular mechanics) module relying either on non-polarizable or polarizable force fields. QM/MM methodologies available in deMon2k include ground-state geometry optimizations, ground-state Born–Oppenheimer molecular dynamics simulations, Ehrenfest non-adiabatic molecular dynamics simulations, and attosecond electron dynamics. In addition several electric and magnetic properties can be computed with QM/MM. We review the framework implemented in the program, including the most recently implemented options (link atoms, implicit continuum for remote environments, metadynamics, etc.), together with six applicative examples. The applications involve (i) a reactivity study of a cyclic organic molecule in water; (ii) the establishment of free-energy profiles for nucleophilic-substitution reactions by the umbrella sampling method; (iii) the construction of two-dimensional free energy maps by metadynamics simulations; (iv) the simulation of UV-visible absorption spectra of a solvated chromophore molecule; (v) the simulation of a free energy profile for an electron transfer reaction within Marcus theory; and (vi) the simulation of fragmentation of a peptide after collision with a high-energy proton.

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Monchick, L., and L. W. Hunter. "Diatomic–diatomic molecular collision integrals for pressure broadening and Dicke narrowing: A generalization of Hess’s theory." Journal of Chemical Physics 85, no. 2 (July 15, 1986): 713–18. http://dx.doi.org/10.1063/1.451277.

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Skvortsov, V. A. "Numerical calculation of collision matrix in theory of molecular-line broadening and shift by gas pressure." Radiophysics and Quantum Electronics 36, no. 9 (September 1993): 654–57. http://dx.doi.org/10.1007/bf01038211.

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Rabrenović, M., J. H. Beynon, S. H. Lee, and M. S. Kim. "Collision-induced dissociation of keV methane molecular ions. Analysis of the pressure dependence using probability theory." International Journal of Mass Spectrometry and Ion Processes 65, no. 1-2 (May 1985): 197–210. http://dx.doi.org/10.1016/0168-1176(85)85064-3.

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Perez, Evan, Theodore A. Corcovilos, John K. Gibson, Jonathan Martens, Giel Berden, Jos Oomens, and Michael J. Van Stipdonk. "Isotope labeling and infrared multiple-photon photodissociation investigation of product ions generated by dissociation of [ZnNO3(CH3OH)2]+: Conversion of methanol to formaldehyde." European Journal of Mass Spectrometry 25, no. 1 (February 2019): 58–72. http://dx.doi.org/10.1177/1469066718809881.

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Electrospray ionization was used to generate species such as [ZnNO3(CH3OH)2]+ from Zn(NO3)2•XH2O dissolved in a mixture of CH3OH and H2O. Collision-induced dissociation of [ZnNO3(CH3OH)2]+ causes elimination of CH3OH to form [ZnNO3(CH3OH)]+. Subsequent collision-induced dissociation of [ZnNO3(CH3OH)]+ causes elimination of 47 mass units (u), consistent with ejection of HNO2. The neutral loss shifts to 48 u for collision-induced dissociation of [ZnNO3(CD3OH)]+, demonstrating the ejection of HNO2 involves intra-complex transfer of H from the methyl group methanol ligand. Subsequent collision-induced dissociation causes the elimination of 30 u (32 u for the complex with CD3OH), suggesting the elimination of formaldehyde (CH2 = O). The product ion is [ZnOH]+. Collision-induced dissociation of a precursor complex created using CH3-18OH shows the isotope label is retained in CH2 = O. Density functional theory calculations suggested that the “rearranged” product, ZnOH with bound HNO2 and formaldehyde is significantly lower in energy than ZnNO3 with bound methanol. We therefore used infrared multiple-photon photodissociation spectroscopy to determine the structures of both [ZnNO3(CH3OH)2]+ and [ZnNO3(CH3OH)]+. The infrared spectra clearly show that both ions contain intact nitrate and methanol ligands, which suggests that rearrangement occurs during collision-induced dissociation of [ZnNO3(CH3OH)]+. Based on the density functional theory calculations, we propose that transfer of H, from the methyl group of the CH3OH ligand to nitrate, occurs in concert with the formation of a Zn–C bond. After dissociation to release HNO2, the product rearranges with the insertion of the remaining O atom into the Zn–C bond. Subsequent C–O bond cleavage, with H transfer, produces an ion–molecule complex composed of [ZnOH]+ and O = CH2.

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Igbagara, Princewill. "Simulation of an Industrial Carbon Black Reactor Using Collision Kinetics." European Journal of Physical Sciences 4, no. 1 (August 1, 2021): 35–48. http://dx.doi.org/10.47672/ejps.753.

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Purpose: Objective of the work was to test efficacy of the proposed flame chemistry and collision kinetics for prediction of process parametres through determination of the effect of basic process parameters on yield (which includes but not limited to grade of carbon black produced). Methodology: The research methodology in this work was simulation of an industrial Carbon Black Reactor based on reaction kinetics from flame chemistry which assumes that primary particle formation and particle growth is strictly by collision of molecular nuclei with gas molecule as proposed by the collision theory. Decant oil from the Fluid Catalytic Cracking Unit (FCCU) of the Warri Refinery and Petrochemical Company Limited of Nigeria represented by naphthalene was used as feedstock in the simulation while methane gas is the fuel for combustion needed to attain the reaction temperature. Findings: Results showed an excellent quantitative prediction of trends by models. Qualitative predictions gave far higher parameter values, something easily attributable to the excessively high values of kinetic data used for model testing. Recommendation: The simplifying assumptions of these models completely ignored microscopic phenomena such as interface mass and heat transfer and other similar processes. Consequently, the model can be improved upon by introducing some of these processes as identified.

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Allard, Nicole F., John F. Kielkopf, Siyi Xu, Grégoire Guillon, Bilel Mehnen, Roberto Linguerri, Muneerah Mogren Al Mogren, Majdi Hochlaf, and Ivan Hubeny. "H–He collision-induced satellite in the Lyman α profile of DBA white dwarf stars." Monthly Notices of the Royal Astronomical Society 494, no. 1 (March 13, 2020): 868–75. http://dx.doi.org/10.1093/mnras/staa707.

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ABSTRACT The spectra of helium-dominated white dwarf stars with hydrogen in their atmosphere present a distinctive broad feature centred around 1160 Å in the blue wing of the Lyman α line. It is extremely apparent in WD 1425+540 recently observed with Hubble Space Telescope(HST) Cosmic Origins Spectrograph (COS). With new theoretical line profiles based on ab initio atomic interaction potentials we show that this feature is a signature of a collision-induced satellite due to an asymptotically forbidden transition. This quasi-molecular spectral satellite is crucial to understanding the asymmetrical shape of Lyman α seen in this and other white dwarf spectra. Our previous work predicting this absorption feature was limited by molecular potentials that were not adequate to follow the atomic interactions with spectroscopic precision to the asymptotic limit of large separation. A new set of potential energy curves and electronic dipole transition moments for the lowest electronic states of the H–He system were developed to account accurately for the behaviour of the atomic interactions at all distances, from the chemical regime within 1 Å out to where the radiating H atoms are not significantly perturbed by their neighbours. We use a general unified theory of collision-broadened atomic spectral lines to describe a rigorous treatment of hydrogen Lyman α with these potentials and present a new study of its broadening by radiative collisions of hydrogen and neutral helium. These results enable ab initio modelling of radiative transport in DBA white dwarf atmospheres.

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BULUT, MEVLUT, and RENATO P. CAMATA. "A GENERALIZED CELL METHOD FOR HARD DISK MOLECULAR DYNAMICS SIMULATION OF POLYDISPERSE SYSTEMS." International Journal of Modern Physics C 18, no. 09 (September 2007): 1407–16. http://dx.doi.org/10.1142/s0129183107011418.

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Hard Disk Molecular Dynamics (HDMD) techniques often exhibit significant loss in calculation speed when applied to the simulation of highly polydisperse particle systems. The collision rate of the reported algorithms may be lower by as much as two orders of magnitude if compared to the collision rate of a monodisperse system of the same number of particles. This is mainly due to the fact that the rectangular cells in the simulation domain used in HDMD methods must meet a certain size criterion. In this paper, we introduce a cell technique that removes the requirement on the cell size enabling simulation of particles with sizes much larger than the cell size. This approach improves the collision rates in the simulation of tested polydisperse systems by factors ranging from 5.5 to 57 depending on the size distribution of the particle population simulated. This may enable the simulation of grand canonical systems in which the size and the number of particles can change throughout the simulation. The technique is compatible with the simulation of disk-like as well as irregularly shaped particles and can be extended to three dimensions.

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Yasuda, Masaaki, Shinya Wakuda, Yoshiki Asayama, Hiroaki Kawata, and Yoshihiko Hirai. "Interaction volume of electron beam in carbon nanomaterials: A molecular dynamics study." MRS Proceedings 1700 (2014): 29–35. http://dx.doi.org/10.1557/opl.2014.675.

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ABSTRACTA molecular dynamics (MD) simulation was performed to study the interaction volume of electron beam in carbon nanomaterials. The interaction between incident electron and carbon atom in the target materials during electron irradiation is introduced by the relativistic binary collision theory. The motion of each atom in the material under electron irradiation is calculated with the MD simulation. The primary energy dependence of the interaction volume in the carbon nanotube and the multi-layered graphene are studied. The secondary damages caused by the knock-on atoms are also discussed.

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Brôuning, H., L. P. Presnyakov, A. A. Narits, A. Diehl, R. Trassl, A. Theiβ, and E. Salzborn. "Charge transfer in the collision system He2+ + C 60 + : Theory and experiment." Journal of Russian Laser Research 26, no. 1 (January 2005): 26–32. http://dx.doi.org/10.1007/s10946-005-0003-7.

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