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Dynamics of flexible peptides under the action of an electrostatic field in the gas phase. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.07.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Koutselos AD. Transport and dynamic properties of O2+(X2Πg) in Kr under the action of an electrostatic field: single or multiple potential energy surface treatment. J Chem Phys 2011; 134:194301. [PMID: 21599053 DOI: 10.1063/1.3589164] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ion transport and dynamic properties are calculated through molecular dynamics simulation of the motion of O(2)(+) in Kr under the action of an electrostatic field. The two lower potential energy surfaces X̃(2)A(") and Ã(2)A(') are considered for the interaction of the Π ground state of the ion with a closed shell noble gas. First, we study the reproduction of experimental mobility data through the use of single and multiple potential energy surfaces and establish the contribution of both lower energy states to the interactions. Further, we obtain mean energies and components of the diffusion coefficient parallel and perpendicular to the field, the latter through calculation of the velocity correlation functions. We also calculate components of the angular momentum which provide a measure of the collisional rotational alignment of the ions at high field strength.
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Affiliation(s)
- Andreas D Koutselos
- Physical Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens, Greece.
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Viggiano AA. Reexamination of ionospheric chemistry: high temperature kinetics, internal energy dependences, unusual isomers, and corrections. Phys Chem Chem Phys 2006; 8:2557-71. [PMID: 16738710 DOI: 10.1039/b603585j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A number of aspects of ionospheric chemistry are revisited. The review discusses in detail only work performed at AFRL, but other work is mentioned. A large portion of the paper discusses measurements of the kinetics of upper ionospheric reactions at very high temperatures, i.e. the upper temperature range has been extended to at least 1400 K and in some cases to 1800 K. These temperatures are high enough to excite vibrations in O2, N2, and NO and comparing them to drift tube data allows information on the rotational temperature and vibrational level dependences to be derived. Rotational and translational energy are equivalent in controlling the kinetics in most reactions. Vibrational energy in O2 and N2 is often found to promote reactivity which is shown to cause ionospheric density depletions. NO vibrations do not significantly affect the reactivity. In a number of cases, detailed calculations accompanied the experimental studies and elucidated details of the mechanisms. Kinetics of two peroxide isomers important in the lower ionospheric have been measured for the first time, i.e. NOO+ and ONOO-. Finally, two examples are shown where errors in previous data are corrected.
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Affiliation(s)
- A A Viggiano
- Air Force Research Laboratory, Space Vehicles Directorate, 29 Randolph Rd., Hanscom Air Force Base, MA 01731-3010, USA
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Viehland LA, Goeringer DE. Kinetic theory of radio frequency quadrupole ion traps. I. Trapping of atomic ions in a pure atomic gas. J Chem Phys 2004; 120:9090-103. [PMID: 15267845 DOI: 10.1063/1.1691405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A kinetic theory based on the Boltzmann equation is developed for the trapping of atomic ions in a radio-frequency quadrupole ion trap containing enough neutral atoms that ion-neutral collisions cannot be ignored. The collisions are treated at the same level of sophistication and detail as is used to deal with the time- and space-dependent electric fields in the trap. As a result, microscopic definitions are obtained for the damping and stochastic forces that originate from such collisions. These definitions contrast with corresponding phenomenological terms added ad hoc in previous treatments to create damped Mathieu and Langevin equations, respectively. Furthermore, the theory indicates that either collisional cooling or heating of the ions is possible, depending upon details of the ion-neutral mass ratios and interaction potential. The kinetic theory is not dependent on any special assumptions about the electric field strengths, the ion-neutral interaction potentials, or the ion-neutral mass ratio. It also provides an ab initio way to describe the ion kinetic energies, temperatures, and other properties by a series of successive approximations.
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Affiliation(s)
- Larry A Viehland
- Division of Science, Chatham College, Pittsburgh, Pennsylvania 15232, USA
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Viggiano AA, Morris RA. Rotational and Vibrational Energy Effects on Ion−Molecule Reactivity As Studied by the VT-SIFDT Technique. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp962084x] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. A. Viggiano
- Phillips Laboratory, Geophysics Directorate, Ionospheric Effects Division (GPID), 29 Randolph Road, Hanscom AFB, Massachusetts 01731-3010
| | - Robert A. Morris
- Phillips Laboratory, Geophysics Directorate, Ionospheric Effects Division (GPID), 29 Randolph Road, Hanscom AFB, Massachusetts 01731-3010
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Selected ion flow drift tube studies of the kinetics of the reactions of Si+(2P) with C2H2 and C6H6. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0168-1176(95)04281-o] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Sanderson J, Tanuma H, Kobayashi N, Kaneko Y. Ion mobility measurements for O+ and N+ in helium gas at 4.35 K. J Chem Phys 1995. [DOI: 10.1063/1.470338] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tan TL, Ong PP. Transverse diffusion measurements and Monte Carlo simulation studies of Rb+ ions in Kr and Xe. J Chem Phys 1995. [DOI: 10.1063/1.470640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tan TL, Ong PP, Hogan MJ. Transport properties and interaction potential for Na+ ions in Xe gas. J Chem Phys 1994. [DOI: 10.1063/1.466919] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Pogrebnya S, Freysinger W, Hansel A, Kriegel M, Lindinger W. Relaxation of vibrationally excited ions O+2(v) and NO+ (v) in collisions with He. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/0168-1176(93)87032-n] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Tan TL, Ong PP, Hogan MJ. Transport properties of Na+ ions in Kr gas. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1993; 48:1331-1336. [PMID: 9960718 DOI: 10.1103/physreve.48.1331] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Ferguson E, Van Dorenai JM, Viggiano A, Morris RA, Paulson JF, Stewart J, Sunderlin L, Armentrout P. Internal and translational energy effects on the charge- transfer reaction of CO+2 with O2. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0168-1176(92)80098-l] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Dotan I, Viggiano AA, Morris RA. Rotational temperature dependence of the branching ratio for the reaction of Kr+(2P3/2) ions with HD. J Chem Phys 1992. [DOI: 10.1063/1.462395] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Viggiano AA, Morris RA, Van Doren JM, Paulson JF. The effect of low frequency vibrations in CH4 on the rate constant for the reaction of O+2 (X 2Πg, v=0) with CH4. J Chem Phys 1992. [DOI: 10.1063/1.462515] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Viggiano AA, Morris RA, Van Doren JM, Paulson JF. Temperature, kinetic energy, and internal energy dependences of the rate constant and branching fraction for the reaction of O+ (4S) with CO2. J Chem Phys 1992. [DOI: 10.1063/1.462514] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Viggiano AA, Van Doren JM, Morris RA, Williamson JS, Mundis PL, Paulson JF, Dateo CE. Rotational temperature dependence of the branching ratio for the reaction of O+ with HD. J Chem Phys 1991. [DOI: 10.1063/1.461291] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Viehland LA, Viggiano AA, Mason EA. The Ar+–He interaction potential and distribution function effects on swarm measurements of Ar++N2 reaction‐rate coefficients using helium buffer gas. J Chem Phys 1991. [DOI: 10.1063/1.461406] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Viggiano AA, Morris RA, Dale F, Paulson JF, Giles K, Smith D, Su T. Kinetic energy, temperature, and derived rotational temperature dependences for the reactions of Kr+(2P3/2) and Ar+ with HCl. J Chem Phys 1990. [DOI: 10.1063/1.459178] [Citation(s) in RCA: 176] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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