Atomic spectra, function

Atomic spectra, function, 236 Australia, early coordination chemistry, 127-128 Axial and chirality control in OC-6, coordination compounds, 294,295/296... 

According to Eq. (34), the spectrum can be expressed in terms of the atomic correlation functions as... 

Jakobsons, J., J. Gravitis, V. M. Andrianov, J. Dzehne, and V. G. Dashevsku. 1982. Calculation of frequencies of vibrational spectra of model lignin compounds by the method of atom-atom potential functions. I. Calculation of frequencies of the vibrational spectrum of an aromatic ring. Khim. Drev. 1982(5) 52-57. 

The characteristic feature of the 3d- and 4d-metal electronic structure is a strong localization of the wave functions of valence d-electrons on atoms. The end of the series of transition metals is characterized also by a large number of valence electrons on the atom. That is why the intensities of the second-order processes may be expected to be significant in the 3d- and 4d-metal secondary electron spectra. Considering the EFSs of the secondary electron spectrum—which are located above the low-energy CVV Auger lines (MW in 3d and NW in 4d metals), where the inverse radii of localization of the core-electron wave function are rather small—the values of the parameter natipC are expected to be sufficiently large then the intensity of the second-order process should be comparable to the intensity of the first-order processes in the atomic spectrum of secondary electron emission. 

These same types of molecular motions occm even when other atoms or functional groups are involved in the vibrational transitions. However, depending on the types of atoms involved and their enviromnents in the molecule, each transition will have a specific energy associated with it. Each of these vibrational modes will give rise to the absorption of infrared spectrum. This forms the basis for qualitative analysis and structmal determinations by infrared spectroscopy. For organic molecules, hydrogen... 

By this time, we have introduced so many approximations and restrictions on our wave function and energy spectrum that is no longer quite legitimate to call it a Schroedinger equation (Schroedinger s initial paper treated the hydrogen atom only.) We now write... 

Polyatomic molecules vibrate in a very complicated way, but, expressed in temis of their normal coordinates, atoms or groups of atoms vibrate sinusoidally in phase, with the same frequency. Each mode of motion functions as an independent hamionic oscillator and, provided certain selection rules are satisfied, contributes a band to the vibrational spectr um. There will be at least as many bands as there are degrees of freedom, but the frequencies of the normal coordinates will dominate the vibrational spectrum for simple molecules. An example is water, which has a pair of infrared absorption maxima centered at about 3780 cm and a single peak at about 1580 cm (nist webbook). 

---