Reduced excitation level

TABLE 3. Total energies (E), adiabatic excitation energies (Te), reduced excitations level (REL) values, and dipole moments (/r) of the ground and low-lying excited states of the CH radical, as obtained with the aug-cc-pVTZ (E, Te, and REL) and aug-cc-pVDZ (/r) basis sets [110,111]. Experimental data and nuclear geometries used in the CC/EOMCC calculations are taken from Refs. [113-119]. 

At low p.f.s the generator operates at a low level of excitations (armature reaction demagnetizing). During a fault, therefore, when the p.f. of the circuit falls it will also cause a fall in the excitation level and in turn in the terminal voltage. A low voltage, however, would reduce the severity of the fault. 

When copper is bound to one sulfur atom of a cysteine and two nitrogens of two histidines in an essentially tetrahedrally distorted - trigonal ligand environment (type I copper proteins), the excited levels are low in energy, and the values are reduced to about 5 x 10 ° s (29). Examples are blue copper proteins, like ceruloplasmin and azurin, and copper(II) substituted liver alcohol dehydrogenase (30-32). 

SA node and A-V fibers become dominant. Activation of M2 receptors increases the potassium permeability and reduces cAMP levels, slowing the rate of depolarization and decreasing the excitability of SA node and A-V fiber cells. This results in marked bradycardia and a slowing of A-V conduction that can override the stimulation of the heart by catecholamines released during sympathetic stimulation. In fact, very high doses of a muscarinic agonist can produce lethal bradycardia and A-V block. Choline esters have relatively minor direct effects on ventricular function, but they can produce negative inotropy of the atria. 

Another means to reduce the scale of the problem is to shrink the size of the CAS calculation, but to allow a limited number of excitations from/to orbitals outside of the CAS space. This secondary space is called a restricted active space (RAS), and usually the excitation level is limited to one or two electrons. Thus, while all possible configurations of electrons in the CAS space are permitted, only a limited number of RAS configurations is possible. Remaining occupied and virtual orbitals, if any, are restricted to occupation numbers of exactly two and zero, respectively. 

In conventional gas electron diffraction experiments, an effusive beam is used in which vibrational levels of molecules are thermally populated and the width of a peak in a radial distribution curve is determined by thermally averaged mean amplitudes. When a molecular beam or a free jet is used, mean amplitudes could become small, since the contribution from the vibrationally excited levels is reduced significantly. As a consequence, sharper peaks are expected in the radial distribution curve, and the spatial resolution of the snapshot could be improved. However, it seems that the observed peaks in the radial distribution curve are considerably broad even though a molecular beam is used. There could be some reasons to have such broadened peaks in the radial distribution curve. 

On the other hand, the luminescence quantum efficiency can decrease. Apart from a decrease of the oscillator strengths themselves, many other mechanisms can cause such reduced quantum efficiencies, as, for example, enhanced electron-phonon coupling, generation of new paths for deexcitation or energy transfer processes. In fact, these processes will not affect the oscillator strengths of the transition but simply influence the occupation of the excited level. Therefore, the oscillator strength of a given transition may still increase under pressure, however, this increase is completely covered up by a fast depletion of the excited level. 

This was defensible in the inert-gas solids (though we noted that the gap was slightly reduced in those solids), but in the ionic crystal the nonmctallic ion electronic levels are greatly raised and the important excited levels (for exciton levels as well as for lower conduction-band levels) are dominated by the states on metallic ions see Fig. 14-1. Pantelides noted in fact that a critical study of the analysis of experiments in terms of the independent-ion model did not support the model. The model appeared to work for the alkali halides, but this was by fitting 16 experimental numbers with 8 adjustable parameters and the systematic variation made this fitting possible. Little success was had with other compounds. 

The maximum concentration of NO(u = 1) observed is 0.1 mm. of Hg and this represents a 500-fold overpopulation of this level at room temperature. The second excited level can also just be detected, but its concentration and that of higher levels are rapidly reduced by resonance exchange reactions of the type... 

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