Interpolated potential energy surface and dynamics for the reactions between N(4S) and H3+(1A1′)

An ab initio potential energy surface for the quartet electronic state of NH3+ has been constructed at the MP2/6-31G(d,p) level of theory. The accuracy of this surface has been verified by comparison with high levels of theory. Classical simulations of the collision of N(4S) and H3+(1A1′) showed no reaction to form NH2++H at thermal energies. The possibility of reaction via surface hopping to the doublet electronic state has been investigated by calculation of the quartet–doublet energy gap at the MRCI/6-311+G(2df,p) level of theory. No evidence of surface crossing could be found for configurations accessible at thermal energies.

[1]  M. A. Collins,et al.  Convergence of molecular potential energy surfaces by interpolation: Application to the OH+H2→H2O+H reaction , 1995 .

[2]  G. Herzberg.  Molecular Spectra and Molecular Structure IV. Constants of Diatomic Molecules , 1939 .

[3]  Michael A. Collins,et al.  Potential energy surfaces and dynamics for the reactions between C(3P) and H3+(1A1′) , 1998 .

[4]  M. A. Collins,et al.  The utility of higher order derivatives in constructing molecular potential energy surfaces by interpolation , 1995 .

[5]  Eric Herbst,et al.  The formation and depletion of molecules in dense interstellar clouds , 1973 .

[6]  P. Knowles,et al.  An efficient method for the evaluation of coupling coefficients in configuration interaction calculations , 1988 .

[7]  E. Ferguson,et al.  Reactions of some hydrocarbon cations with nitrogen atoms , 1986 .

[8]  P. Knowles,et al.  An efficient second-order MC SCF method for long configuration expansions , 1985 .

[9]  F. Fehsenfeld,et al.  Thermal‐Energy Ion—Neutral Reaction Rates. VII. Some Hydrogen‐Atom Abstraction Reactions , 1967 .

[10]  P. Knowles,et al.  An efficient internally contracted multiconfiguration–reference configuration interaction method , 1988 .

[11]  M. A. Collins,et al.  Molecular potential energy surfaces by interpolation , 1994 .

[12]  D. Bonchev,et al.  Chemical group theory : techniques and applications , 1995 .

[13]  Peter Lancaster,et al.  Curve and surface fitting - an introduction , 1986 .

[14]  J. Paulson,et al.  An experimental survey of the reactions of NHn+ ions (n = 0 to 4) with several diatomic and polyatomic molecules at 300 K , 1980 .

[15]  H. W. Schranz,et al.  An efficient microcanonical sampling procedure for molecular systems , 1991 .

[16]  J. Mason,et al.  Algorithms for approximation , 1987 .

[17]  P. Knowles,et al.  A second order multiconfiguration SCF procedure with optimum convergence , 1985 .

[18]  W. Huntress,et al.  Laboratory studies of bimolecular reactions of positive ions in interstellar clouds, in comets, and in planetary atmospheres of reducing composition. [Distributions, rate constants] , 1977 .

[19]  Michael A. Collins,et al.  An interpolated unrestricted Hartree–Fock potential energy surface for the OH+H2→H2O+H reaction , 1996 .

[20]  Michael A. Collins,et al.  Molecular potential-energy surfaces by interpolation: Furtherrefinements , 1997 .

[21]  A. D. McLean,et al.  A detailed investigation of proposed gas-phase syntheses of ammonia in dense interstellar clouds. , 1987, The Astrophysical journal.