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Articles 1 - 15 of 15

Full-Text Articles in Physical Sciences and Mathematics

The Analysis Of Muonium Hyperfine Interaction Measurements Of Thermal Rate Constants For Addition Reactions, Ronald Duchovic, A Wagner, R Turner, D Garner, D Fleming Oct 2014

The Analysis Of Muonium Hyperfine Interaction Measurements Of Thermal Rate Constants For Addition Reactions, Ronald Duchovic, A Wagner, R Turner, D Garner, D Fleming

Ronald J. Duchovic

A new model is developed for the analysis of muon spin relaxation (mu-SR) measurements of muonium (Mu) reaction rates with other chemical species. The kinetics component of the model is specifically developed for addition reactions but can be extended to direct reactions. The polarization component of the model assumes that the adduct formed possesses a single, effective spin precession frequency. The complete model is solved to obtain an analytic expression for the mu-SR signal as a function of time. Both a time-ordered sequence method and a Boltzmann spin equation method give equivalent solutions. These solutions are analyzed under various kinetic …


Teaching College General Chemistry: Techniques Designed To Communicate A Conceptual Framework, Ronald Duchovic Oct 2014

Teaching College General Chemistry: Techniques Designed To Communicate A Conceptual Framework, Ronald Duchovic

Ronald J. Duchovic

General chemistry at the college level is often perceived as a major hurdle by typical undergraduates. Both Freshmen and more advanced students undertake courses in general chemistry either ill-prepared or convinced that the subject matter is beyond their comprehension. With the exception of potential chemistry majors, the vast majority of general chemistry students enter the class simply to satisfy a graduation requirement of their degree program. Consequently, instructors must both communicate an understanding of the subject matter and overcome major barriers to the learning process itself. This paper discusses two techniques which have been utilized for five semesters in general …


Mustard Gas: Its Pre-World War I History, Ronald Duchovic, Joel Vilensky Oct 2014

Mustard Gas: Its Pre-World War I History, Ronald Duchovic, Joel Vilensky

Ronald J. Duchovic

No abstract provided.


Erratum: Theoretical Characterization Of The Potential Energy Surface For H + O2 Ho2* Oh + O. Iii. Computed Points To Define A Global Potential Energy Surface, S Walch, Ronald Duchovic Oct 2014

Erratum: Theoretical Characterization Of The Potential Energy Surface For H + O2 Ho2* Oh + O. Iii. Computed Points To Define A Global Potential Energy Surface, S Walch, Ronald Duchovic

Ronald J. Duchovic

No abstract provided.


A Quasiclassical Trajectory Study Of The Reaction H + O2 Oh + O With The O2 Reagent Vibrationally Excited, Ronald Duchovic, Marla Parker Oct 2014

A Quasiclassical Trajectory Study Of The Reaction H + O2 Oh + O With The O2 Reagent Vibrationally Excited, Ronald Duchovic, Marla Parker

Ronald J. Duchovic

No abstract provided.


Potlib 2001: A Potential Energy Surface Library For Chemical Systems, Ronald Duchovic, Y Volobuev, G Lynch, D Truhlar, T Allison, A Wagner, B Garret, J Corchado Oct 2014

Potlib 2001: A Potential Energy Surface Library For Chemical Systems, Ronald Duchovic, Y Volobuev, G Lynch, D Truhlar, T Allison, A Wagner, B Garret, J Corchado

Ronald J. Duchovic

POTLIB 2001 is a computer program library of global chemical potential energy surface (PES) functions (91 functions in version 1.0) along with test data, a suite of utility programs, and a convenient user interface. The PES programs are written in ANSI standard FORTRAN77 and can be used to determine the Born–Oppenheimer potential energy of chemical systems as a function of the internal coordinates. The accompanying test data allow users to verify local implementations of this library. Finally, the utility programs permit use of this library in conjunction with a variety of chemical dynamics and chemical kinetics computer codes. Interface routines …


Thermal Rate Constants For H + Ch3  Ch4 Recombination. Ii. Comparison Of Experiment And Canonical Variational Transition State Theory, W Hase, S Mondro, Ronald Duchovic, D Hirst Oct 2014

Thermal Rate Constants For H + Ch3  Ch4 Recombination. Ii. Comparison Of Experiment And Canonical Variational Transition State Theory, W Hase, S Mondro, Ronald Duchovic, D Hirst

Ronald J. Duchovic

Canonical variational transition state theory is used to calculate bimolecular rate constants for H + CH, and D + CH, recombination. The calculations are performed on an analytic potential energy surface derived from recent ab initio calculations. Rate constants calculated for this surface are in very good agreement with the experimental values. The H(D)- - -CH3 transitional rocking modes are treated as quantum harmonic oscillators or classical hindered rotors in the calculations. These two treatments give rate constants which agree to within 15%. The variational transition states become tighter as the temperature is increased.


[Erratum] A Correction To The Potlib Library Described In "Potlib 2001: A Potential Energy Surface Library For Chemical Systems": [Computer Physics Communications 144 (2002) 169-187], Ronald Duchovic Oct 2014

[Erratum] A Correction To The Potlib Library Described In "Potlib 2001: A Potential Energy Surface Library For Chemical Systems": [Computer Physics Communications 144 (2002) 169-187], Ronald Duchovic

Ronald J. Duchovic

No abstract provided.


Venus96: A General Chemical Dynamics Computer Program, W Hase, Ronald Duchovic, X Hu, A Komornicki, K Lim, D-H Lu, G Peslherbe, K Swamy, S Vande Linde, A.J Varandas, H Wang, R Wolf Oct 2014

Venus96: A General Chemical Dynamics Computer Program, W Hase, Ronald Duchovic, X Hu, A Komornicki, K Lim, D-H Lu, G Peslherbe, K Swamy, S Vande Linde, A.J Varandas, H Wang, R Wolf

Ronald J. Duchovic

No abstract provided.


The Fft Method For Determining Semiclassical Eigenvalues: Application To Asymmetric Top Rigid Rotors, Ronald Duchovic, G Schatz Oct 2014

The Fft Method For Determining Semiclassical Eigenvalues: Application To Asymmetric Top Rigid Rotors, Ronald Duchovic, G Schatz

Ronald J. Duchovic

A Fourier transform method for calculating action variables and semiclassical eigenvalues in molecules starting from Cartesian coordinates and momenta is developed and applied to the determination of rotational semiclassical eigenvalues for rigid asymmetric top molecules. The method involves calculating rotational actions by using Fourier representations of the symmetric top action‐angle variables to express the integrals. The question of what is the optimum quantization axis is considered, and it is found that the same primitive semiclassical eigenvalues are obtained independent of which principal axis is used for quantization provided that the replacement J → J+ 1/2 is made. The replacement J …


An Application Of Conventional Transition State `Theory To Compute High--Pressure Limit Thermal Rate Coefficients For The Reaction: H(D) + O2  H(D)O2*  Oh(D) + O, Ronald Duchovic, J Pettigrew Oct 2014

An Application Of Conventional Transition State `Theory To Compute High--Pressure Limit Thermal Rate Coefficients For The Reaction: H(D) + O2  H(D)O2*  Oh(D) + O, Ronald Duchovic, J Pettigrew

Ronald J. Duchovic

Several ab initio studies have focused on the minimum energy path region of the hydroperoxyl potential energy surface (PES) (J. Chem. Phys. 1988, 88, 6273) and the saddle point region for H-atom exchange via a T-shaped HO2 complex (J. Chem. Phys. 1989, 91, 2373). Further, the results of additional calculations (J. Chem. Phys. 1991, 94, 7068) have been reported which, when combined with the earlier studies, provide a global description (but not an analytic representation) of the PES for this reaction. In this work, information at the stationary points of the ab initio PES is used within the framework of …


Conventional Transition State Theory/Rice-Ramsperger-Kassel-Marcus Theory Calculations Of Thermal Termolecular Rate Coefficients For H(D) + O2 + M, Ronald Duchovic, J Pettigrew, B Welling, T Shipchandler Oct 2014

Conventional Transition State Theory/Rice-Ramsperger-Kassel-Marcus Theory Calculations Of Thermal Termolecular Rate Coefficients For H(D) + O2 + M, Ronald Duchovic, J Pettigrew, B Welling, T Shipchandler

Ronald J. Duchovic

Several ab initio studies have focused on the minimum energy path region of the hydroperoxyl potential energy surface (PES) [J. Chem. Phys. 88, 6273 (1988)] and the saddle point region for H‐atom exchange via a T‐shaped HO2 complex [J. Chem. Phys. 91, 2373 (1989)]. Further, the results of additional calculations [J. Chem. Phys. 94, 7068 (1991)] have been reported, which, when combined with the earlier studies, provide a global description (but not an analytic representation) of the PES for this reaction. In this work, information at the stationary points of theab initio PES is used within the framework of conventional …


Teaching Science To The Non-Science Major: An Interdisciplinary Approach, Ronald Duchovic, David Maloney, A Majumdar, R Manalis Oct 2014

Teaching Science To The Non-Science Major: An Interdisciplinary Approach, Ronald Duchovic, David Maloney, A Majumdar, R Manalis

Ronald J. Duchovic

No abstract provided.


Theoretical Characterization Of The Minimum Energy Path For Hydrogen Atom Addition To N2: Implications For The Unimolecular Lifetime Of Hn2, S Walch, Ronald Duchovic, C Rohlfing Oct 2014

Theoretical Characterization Of The Minimum Energy Path For Hydrogen Atom Addition To N2: Implications For The Unimolecular Lifetime Of Hn2, S Walch, Ronald Duchovic, C Rohlfing

Ronald J. Duchovic

The minimum energy path (MEP) for the addition of a hydrogen atom to N2 is characterized in CASSCF/externally contracted CI calculations using a [4s3p2d1f/3s2p1d] ANO basis set, with additional single point calculations at the stationary points of the potential energy surface using a [5s4p3d2f/4s3p2s] ANO basis set. These calculations represent the most extensive set of ab initio calculations on HN2 completed to date, yielding a zero-point corrected barrier for HN2 dissociation of ?8.5 kcal mol-1. The lifetime of the HN2 species is estimated from the calculated geometries and energetics using both conventional transition state theory and a method which utilizes …


The Evolution Of Billfish, Andrew Blitman Dec 2013

The Evolution Of Billfish, Andrew Blitman

Andrew Blitman

No abstract provided.