Potential energy surface of ground

On the other hand, the dynamics of the bond dissociations (i.e. the motion of the representative wave packet on the potential energy surfaces of ground and excited states for the various molecular entities) turns out to be always the same. This is concluded from the fact that the final state of the desorbing NO stays constant all energy distributions, translational, rotational, and vibrational, as well as their correlations, are identical despite the strong variations of cross sections [14, 96], These characteristics are compatible with the proposed TNI mechanism (see item 2 in... 

Fe(CO)s were able to characterize the structure of several unsaturated intermediates.Fe(CO>5 was deposited in dilute Ar, CH4, or SF5 matrices at ca. 10 K. UV irradiation generated mainly triplet Fe(CO>4 ( Fe(CO)4). Figure 10 shows the results obtained following irradiation of Fe(CO)s in an SFe matrix. The IR spectrum of Fe(CO)4 was consistent with a C2, structure, and quantum mechanical calculations found the C21, structure to be the energetic minimum on the potential energy surface of ground state Fe(CO>4. 

Recalibration of a Single-Valued Double Many-Body Expansion Potential-Energy Surface of Ground-State HO2 and Dynamics Calculations for the O -F OH — H -F O2 Reaction J. Troe and V. G. Ushakov, /. Chem. Phys., 115,3621 (2001). Theoretical Studies of the HO-F O HO2 H-F O2 Reaction, n. Classical Trajectory Calculations on an Ab Initio Potential for Temperatures Between 300 and 5000 K. 

All of the above considerations can be illustrated in the course of a discussion of the potential energy surfaces of ground and excited state, and their interaction. 

Fig. 13.5. Schematic representation of the potential energy surfaces of the ground state (S ,) and the excited state (.5,) of a nonadiabatic photoreaction of reactant R. Depending on the way the classical trajectories enter the conical intersection region, different ground-state valleys, which lead to products P and can be reached. Reproduced from Angew. Chem. Int. Ed. Engl. 34 549 (1995) by permission of Wiley-VCH.

Figure 11. Contour plot of the adiabatic ground potential energy surface of the 2D model. The dashed line shows the seam surface. Taken from Ref. [27].

Figure 18. Contour plots of the potential energy surfaces of the first three electronic states of H2O. The polar plots depict the movement of one H atom around OH with an OH bond length fixed at 1.07 A. Energies are in electron volts relative to the ground electronic state. The X and B states are degenerate at the conical intersection (denoted by (g)) in the (a) H—OH geometry and (b) H—HO geometry. Reprinted fix)m [75] with permission from the American Association for the Advancement of Science.

Figure 7. Two-dimensional cut of the ground- and excited-state adiabatic potential energy surfaces of Li + H2 in the vicinity of the conical intersection. The Li-EL distance is fixed at 2.8 bohr, and the ground and excited states correspond to Li(2,v) + H2 and Lit2/j ) + H2, where the p orbital in the latter is aligned parallel to the H2 molecular axis, y is the angle between the H-H intemuclear distance, r, and the Li-to-H2 center-of-mass distance. Note the sloped nature of the intersection as a function of the H-H distance, r, which occurs because the intersection is located on the repulsive wall. (Figure adapted from Ref. 140.)...

The same kind of isomerization can also be enforced in the parent compound, namely nitrosohydrogen HNO (150).198 Matrix irradiation of 150 leads to isonitroso hydrogen NOH (151). Calculations of the potential-energy surface of the system HNO/HON show a singlet ground state for HNO 150, which is also the global minimum.199 200 However, for HON 151 a triplet ground state is predicted. Indeed, the experimental IR spectrum of 151 fits much better the calculated spectrum of the triplet. Thus, the isomerization 150 151 involves... 

Banichevich, A., S. D. Peyerimhoff, and F. Grein, Potential Energy Surfaces of Ozone in Its Ground State and in the Lowest-Lying Eight Excited States, Chem. Phys., 178, 155-188 (1993). 

This section presents X-ray diffraction, dynamic NMR and theoretical data on the conformations of heterocyclic eight-membered rings. Ideally, it would be desirable to know the whole conformational potential energy surface of the ground electronic state of a molecule. In practice, the lowest (and perhaps the second lowest) energy conformation can be more or less characterized, and some conformational energy barriers can be determined and calculated. 

Fig. 7. Potential energy surfaces for ground and first excited state of Mo2(DXylF)2(02CCH3)2(n2-0)2 complex. The pseudo-Jahn-Teller effect results from a coupling between So and the excited 1( 6 ) state, causing the central Mo2(p2-0)2 motif to be rhomboidal (C2h), rather than square (D2h) [Adapted from Ref. (55) with permission].

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