Faculty

Richard N. PorterRichard N. Porter, Professor Emeritus

B.S., 1954, Texas A & M University
Ph.D., 1960, University of Illinois

 

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Theoretical Chemistry

Our main interests are in the theory of chemical reactions resulting from molecular collisions, in the theory of nuclear motion in small stable molecules, and in many-body and field-theoretic formulation of the properties of molecules and collision complexes. The work makes use of both classical mechanics and quantum mechanics, and involves both analytical mathematics and computer calculations. Our goal is to be able to predict with increasing reliability the reactivity of small molecules in the gas phase and to learn how to modify their reactivity. We calculate the forces that determine atomic motions by both semiempirical (based upon the valence-bond formulation) and ab initio (molecular-orbital theory with configuration interaction) approaches. Once we have the forces on the atoms, we solve the problem of their motion by either a quantum-mechanical calculation or by analyzing classical trajectories, depending upon whether the system is a stable molecule or a collision complex. The results for the atomic motion are then used to obtain reaction cross-sections and rate coefficients under various external conditions. Our ab initio calculations of the rotation-vibration spectra of H3+ have facilitated the identification of the recently observed infrared spectra of this molecular ion. We have just begun analysis of the interaction of photons with molecular ensembles with particular attention to coherence and chaos. Three of the fields in which our work finds application are isotope separation, laser chemistry, and the chemistry of the interstellar medium.

Positions/Awards/Honors

  • Research Associate, University of Illinois, 1960-61
  • Research Associate, Columbia University, 1961-62
  • Alfred P. Sloan Fellowship, 1968-72
  • U.S. Senior Scientist Award of the Humboldt Foundation, 1978
  • Visiting Fellow of the Joint Institute for Laboratory Astrophysics, 1969-70
  • Visiting Professor, Harvard University, 1973, 1980, and 1987

Publications

R.D. Gilbert and R.N. Porter, "Non-Perturbative Calculation of Energies and Widths of Predissociative States of Diatomic Molecules," J. Chem. Phys. 89, 3057 (1988).

Y. Zang and R.N. Porter, "The Nuclear Displacement Operator and Formulation of The Born Couplings of Molecular Born-Oppenheimer Wave Functions," J. Chem. Phys. 88, 4949 (1988).

Y. Zhang, N. Sukumar, J. L. Whitten, and R.N. Porter, "Ab Initio Evaluation of the Born Correction, Born Couplings, and Higher Derivative Matrix Elements with Gaussian-Lobe Orbitals," J. Chem. Phys. 88, 7662 (1988).

L. Li, R. N. Porter, and P. M. Johnson, "Pressure Narrowing of ac Stark-SBroadened Multi- photon Spectra," Phys. Rev. Lett. 53, 1336 (1984); 54, 367 (1985).

G.D. Carney and R.N. Porter, "Ab Initio Prediction of the Rotation-Vibration Spectrum of H3+D3+, "Phys. Rev. Lett. 45, 537 (1980).

P. Angerhofer, E. Churchwell,2 and R.N. Porter, "A Search for Circumstellar and Interstellar H2D+,"Astrophys. Let. 19, 137 (1978).

R.N. Porter, "State-to-State Considerations in Reactions in Interstellar Clouds," in ACS Symposium Series, No. 56, State-to-State Chemistry (P.R. Brook and E.F. Hayes, eds.) American Chemical Society: Washington, D.C., 236 (1977).

G.D. Garney and R.N. Porter, "The Lowest Rotation States of H3+ and Symmetry Considerations in Dissociative e-Capture," J. Chem. Phys. 66, 2756 (1977).

H.K. McDowell and R.N. Porter, "Reduced Green's Functions and Coupled Perturbed Hartree-Fock Calculations. II. Application to the Static Dipole Polarizability of the Helium Isoelectronic Sequence," J. Chem. Phys. 66, 4725 (1977).

R.N. Porter and L.M. Raff, "Classical Trajectory Methods in Molecular Colisions, Part B," (W.H. Miller, ed.) Plenum: New York, 1-52 (1976)

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