Spin-orbit corrected full-dimensional potential energy surfaces for the two lowest-lying electronic states of FH2O and dynamics for the F + H2O → HF + OH reaction

In a previous paper (G. Osmann et al. J. Mol. Spectrosc. 197, 262 (1999)) we calculated ab initio the potential-energy surfaces of the ground [Formula: see text]2A" and excited Ã2A' electronic states of the HO2 molecule; these two states correlate with a 2Π state at linearity and participate in a Renner effect interaction. In that paper, we also calculated the electric- and magnetic-dipole moment and transition-moment surfaces, and the spin-orbit coupling constant; we then simulated the Ã ® [Formula: see text] emission band system including both electric-dipole and magnetic-dipole transitions. We now calculate more points on the surfaces to cover a wider range of bending geometries, and then refine the surfaces by fitting to rovibronic term values for both electronic states simultaneously. In the fitting we include levels having J values up to 9/2 and term values up to about 8000 cm1. In our calculation of the energy levels we allow for the Renner effect and spin-orbit coupling by using our variational computer program RENNER. A good fitting to the data is obtained and as a result we obtain an accurate representation of these two potential surfaces over an energy range of more than 1 eV. We tabulate the vibronic energies up to 1 eV for both HO2 and DO2. We can explain the origin of a perturbation observed in the F1 spin component levels of the Ã(0, 0, 0) vibronic state for J values around 51/2; this is caused by a spin-orbit interaction satisfying Δ N = ± 1 with the F2 spin component levels of the [Formula: see text](1,1,2) vibronic state. Using the new rovibronic energies and wave functions, with our ab initio electric dipole moment and transition moment surfaces, we calculate Stark coefficients and compare them with experiment for some ground vibronic state levels. PACS Nos.: 31.20D, 31.50, 33.10, 33.20E, 35.20D, 35.20J

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Nonadiabatic wave packet dynamics on the coupled / electronic states of NO2 based on new ab initio potential energy surfaces

Chemical Physics ◽

10.1016/s0301-0104(00)00204-4 ◽

2000 ◽

Vol 259 (2-3) ◽

pp. 211-226 ◽

Cited By ~ 56

Author(s):

S. Mahapatra ◽

H. Köppel ◽

L.S. Cederbaum ◽

P. Stampfuß ◽

W. Wenzel

Keyword(s):

Potential Energy ◽

Wave Packet ◽

Ab Initio ◽

Potential Energy Surfaces ◽

Electronic States ◽

Wave Packet Dynamics ◽

Energy Surfaces

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Far-infrared spectra and two-dimensional potential energy surfaces for the out-of-plane ring vibrations of tetrahydrofuran-3-one in its S0 and S1(n,π*) electronic states

The Journal of Chemical Physics ◽

10.1063/1.476335 ◽

1998 ◽

Vol 108 (21) ◽

pp. 8884-8890 ◽

Cited By ~ 1

Author(s):

SooNo Lee ◽

Niklas Meinander ◽

Paul Sagear ◽

Deb N. Nath ◽

Jaan Laane

Keyword(s):

Potential Energy ◽

Infrared Spectra ◽

Potential Energy Surfaces ◽

Electronic States ◽

Far Infrared ◽

Two Dimensional ◽

Out Of Plane ◽

Energy Surfaces ◽

Far Infrared Spectra

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Potential Energy Surfaces

Unimolecular Reaction Dynamics ◽

10.1093/oso/9780195074949.003.0005 ◽

1996 ◽

Author(s):

Tomas Baer ◽

William L. Hase

Keyword(s):

Potential Energy ◽

Potential Energy Surface ◽

Electronic State ◽

Diatomic Molecule ◽

Potential Energy Surfaces ◽

Energy Surface ◽

Electronic States ◽

Dissociation Energies ◽

State Potential ◽

Energy Surfaces

Properties of potential energy surfaces are integral to understanding the dynamics of unimolecular reactions. As discussed in chapter 2, the concept of a potential energy surface arises from the Born-Oppenheimer approximation, which separates electronic motion from vibrational/rotational motion. Potential energy surfaces are calculated by solving Eq. (2.3) in chapter 2 at fixed values for the nuclear coordinates R. Solving this equation gives electronic energies Eie(R) at the configuration R for the different electronic states of the molecule. Combining Eie(R) with the nuclear repulsive potential energy VNN(R) gives the potential energy surface Vi(R) for electronic state i (Hirst, 1985). Each state is identified by its spin angular momentum and orbital symmetry. Since the electronic density between nuclei is different for each electronic state, each state has its own equilibrium geometry, sets of vibrational frequencies, and bond dissociation energies. To illustrate this effect, vibrational frequencies for the ground singlet state (S0) and first excited singlet state (S1) of H2CO are compared in table 3.1. For a diatomic molecule, potential energy surfaces only depend on the internuclear separation, so that a potential energy curve results instead of a surface. Possible potential energy curves for a diatomic molecule are depicted in figure 3.1. Of particular interest in this figure are the different equilibrium bond lengths and dissociation energies for the different electronic states. The lowest potential curve is referred to as the ground electronic state potential. The primary focus of this chapter is the ground electronic state potential energy surface. In the last section potential energy surfaces are considered for excited electronic states. A unimolecular reactant molecule consisting of N atoms has a multidimensional potential energy surface which depends on 3N-6 independent coordinates. For the smallest nondiatomic reactant, a triatomic molecule, the potential energy surface is four-dimensional (three independent coordinates plus the energy). Since it is difficult, if not impossible, to visualize surfaces with more than three dimensions, methods are used to reduce the dimensionality of the problem in portraying surfaces. In a graphical representation of a surface the potential energy is depicted as a function of two coordinates with constraints placed on the remaining 3N-8 coordinates.

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