Electronic energy tabulation

Finally, a comment regarding relativistic effects and the calculation of one-electron energies and monopole relaxation shifts. The most convenient way to obtain relativistic zlSCF one-electron energies is to use the Dirac-Fock-Slater (DFS) zlSCF values tabulated by Huang et al.82). These are very close (a few tenths of an eV) to DF JSCF, and the relativistic monopole relaxation shift is the given by... 

It is an often repeated claim that the HMO rc-electron energies are in good agreement with experimental enthalpies of the respective conjugated compounds. This statement could easily be tested provided experimental enthalpies were available. Unfortunately, they are known only for a limited number of conjugated hydrocarbons. In particular, heats of formation are tabulated for only 24 benzenoid hydrocarbons [20]. 

The electronic energy levels and quantum weights used in the calculation are from Moore (7) and (8). Not all levels are listed above. The tabulated entropy values agree within 0.001 cal K" mol with the recent tabulation by Hultgren et al. (4) and Mah and Pankratz (5). There are predicted levels which have not been observed and/or classified. It Is not expected that S (298.15 K) would be affected by these states, but that in the range 3000-6000K, an error of 0.2-0.3 cal mol might result. In our present tabulation, the levels above 20000 cra" contribute 0.0005 cal K" mol at 3000 K and 0.15 cal K" mol" at 6000 K to the entropy. 

In order to be able to compare calculated thermochemical quantities with experimental values it is necessary to take into account not only electronic energy differences, as tabulated here, but also the vibrational, rotational, translational and work (PV) energy differences5,64. The largest term is usually the vibrational energy difference, which is taken as a sum of zero-point vibrational energies for each molecular species in the chemical... 

The energies involved in Auger spectroscopy are similar in all respects to those of ESC A, since the same atomic shells are involved. A graphical plot of Auger electron energies is shown in Fig. 14.23 and tabulated values of the prominent lines are available in the literature. 

Plots of KE(a) vs. BE(p), with AP + hv shown on the other ordinate (called Wagner plots) are found in the literature and in the NIST XPS database. An example for tin is presented in Fig. 14.25. The Sn 3ds/2 photoelectron and the Sn MNN Auger electron binding energies are tabulated and plotted for the element Sn and a variety of tin compounds, showing how the chemical environment of the Sn affects the electron energies. 

The PH + ion formed by electron impact on PH3 was mass spectrometrically detected. An ionization efficiency curve between 30 and 50 eV led to appearance potentials of 34.0 eV (square root plot) or 32.7 eV (linear extrapolation) [1] both values are tabulated in [2] for the first value, see also [3]. Partial PH3 ionization cross sections for PH + and PD3 ionization cross section ratios, PDl /PD, were obtained for electron energies up to 180 eV and showed appearance potentials of 35.0 0.5 eV for PH + and 34.9 0.5 eV for PD + (square root plots) [4]. The PH + ion was also mass spectrometrically detected after ionization of PH3 by high-energy electrons (8 keV). Oscillator strengths were obtained by dipole (e,e+ion) spectroscopy simulating photoionization [5]. 

Using the HMO approximation, the ir-electron wave function is expressed as a linear combination of atomic orbitals (for the case in which the plane of the molecule coincides with the y-z plane of the coordinate axis), in much the same way as described previously for the generalized MO method. Minimizing the total -jT-electron energy of the molecule with respect to the coefficients (the variation method) leads to a series of equations from which the coefficients can be extracted by way of a secular determinant. The mathematical operations involved in solving the equations are not difficult. We will not describe them in detail, but will instead concentrate on the interpretation of the results of the calculations. For many systems, the Huckel MO energies and atomic coefficients have been tabulated." ... 

Because a large part of the tabulated data is from our own measurements and the rest is based on a large body of literature data a comprehensive reference to published sources is not included. Whenever possible the data refer to conventional modes and conditions of measurement. For example, the chemical shifts for NMR spectra were determined generally in deuterochloroform or carbon tetrachloride. The wave numbers (IR) refer to solvents of low polarity, such as chloroform or carbon disulfide. Mass spectral data were recorded at an electron energy of 70 eV. Most of the data were taken from the following sources ... 

Electronic energies were calculated at the CCSD(T)/cc-pVTZ//MP2/6-31+G(d,p) level, and differences in the negative hydrogenolysis energies tabulated for different correlation methods, except for benzene and benzyne, D. H. Aue, J. E. DelBene, and I. Shavitt. 

Here A(g) represents any gas-phase species, is the DFT electronic energy, is the zero-point correction due to vibrations, P° is a reference pressure often chosen as 1 bar, and AG°(r) = G T,P°) - G 0K,P°) and is calculated either from ideal gas statistical mechanics or from experimental data, often tabulated using the Shomate equation. This form of the Gibbs-Duhem equation is derived assuming ideal gas behavior, which is generally acceptable for the low partial pressures used in catalytic applications, and even for cases where the ideal gas assumption may not be valid it still serves as a first approximation. Applying the 0 K reference state of eqn (2.30), eqn (2.34) can be rewritten as ... 

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