Aron Kuppermann

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The performance of a parallel Gauss-Jordan matrix inversion<supscrpt>1,2</supscrpt> algorithm on the Mark II hypercube<supscrpt>3</supscrpt> at Caltech is discussed. We will show that parallel Gauss-Jordan inversion is superior to parallel Gaussian elimination <italic>for inversion</italic>, and discuss the reasons for this. Empirical and theoretical(More)
Real wave packet propagations were carried out on both a single ground electronic state and two-coupled-electronic states of the title reaction to investigate the extent of nonadiabatic effects on the distinguishable-atom reaction cross sections. The latest diabatic potential matrix of Abrol and Kuppermann [J. Chem. Phys. 116, 1035 (2002)] was employed in(More)
The Hamiltonian for triatomic and tetraatomic systems in row-orthonormal hyperspherical coordinates has been derived previously. However, for pentaatomic systems this derivation requires nontrivial generalizations. These are presented in this paper, together with the corresponding Hamiltonian. Each of the twelve operators that contribute to this Hamiltonian(More)
Use of the Caltech/JPL hypercube multicomputer to solve problems in chemical dynamics is the subject of this paper. The specific application is quantum mechanical atom diatomic molecule reactive scattering. One methodology for solving this dynamics problem on a sequential computer is based on symmetrized hyperspherical coordinates. We will discuss our(More)
Hyperspherical harmonics in the democratic row-orthonormal hyperspherical coordinates are very appropriate basis sets for performing reactive scattering calculations for triatomic and tetraatomic systems. The mathematical conditions for incorporating the geometric phase effect in these harmonics are given. These conditions are implemented for triatomic(More)
A numerical generation method of hyperspherical harmonics for tetra-atomic systems, in terms of row-orthonormal hyperspherical coordinates-a hyper-radius and eight angles-is presented. The nine-dimensional coordinate space is split into three three-dimensional spaces, the physical rotation, kinematic rotation, and kinematic invariant spaces. The eight-angle(More)