Herzberg System

The formation of ozone in the Herzberg System (3) 2 + - 32 , has been studied by Warburg (100). The results are summarized in Table I. It should be emphasized that the results at 125 and 300 kg./cm.2 pressure were obtained in earlier experiments by Warburg (99). 

Quantum Yield of Ozone Formation in the Herzberg Absorption Region 

Experimentally the high pressures were needed since the absorption coefficients are weak in this region. At the pressures used, deviations from 2.0 in the continuous region below 2424 A. may possibly be explained by cage recombination following the formation of two 3P atoms. Above 

The simplest reaction which can explain the fragmentary results is 

At the high pressures used, a geminate reaction between O and 03 to give 02 could then account for the quantum yields of less than two and the decrease of quantum yield with increasing pressure. 

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The main channels to dissociation are by electron excitation to the Schumann and Herzberg systems with practically no contribution of the channel via 02(a1AB)and 02 (b1 ). 

The answer, very often, is that they do not obtain any intensity. Many such vibronic transitions, involving non-totally symmetric vibrations but which are allowed by symmetry, can be devised in many electronic band systems but, in practice, few have sufficient intensity to be observed. For those that do have sufficient intensity the explanation first put forward as to how it is derived was due to Herzberg and Teller. 

Herzberg-Longuet-Higgins phase-based treatment, Jahn-Teller model, 185-186 Jahn-Teller systems, Longuet-Higgins phase, 119-122... 

Herzberg-Longuet-Higgins phase, 185-186 Longuet-Higgins phase, 119-122 two-dimensional two-surface system, quasi-Jahn-Teller scattering calculation, 150-155... 

Herzberg-Longuet-Higgins phase, 185 quantization, 58-59 real system properties, 104—112 C2H-molecule (1,2) and (2,3) conical intersections, 109—112 H3 system and isotopic analogues, 103— 109... 

Herzberg C. T. (1978a). The bearing of phase equilibria in simple and complex systems on the origin and evolution of some garnet websterites. Contrib. Mineral Petrol, 66 375-382. 

Herzberg C. T. (1978b). Pyroxene geothermometry and geobarometry Experimental and thermodynamic evaluation of some subsolidus phase relations involving pyroxenes in the system CaO-MgO-AljOj-SiOj. Geochim. Cosmochim. Acta, 42 945-957. 

FIGURE 4-1 Potential energy curves for ground and first four excited states of 02. S-R = Schumann-Runge system, H = Herzberg continuum, A-A = atmospheric bands (adapted from Gay-don, 1968). 

The ground state is X L+ D0(H—CN) = 5.20 0.05 eV (264). Hydrogen cyanide has no absorption in the visible and near ultraviolet regions. It starts to absorb weakly at about 1900 A. Herzberg and Innes (463) have found three band systems in the region 1350 to 1900 A, corresponding to the y, (I, and a systems. The upper states are all bent. 

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