Stark field, ionic

Camus et a/.34 explained their observations by a picture which has sometimes been called the frozen planet model. Qualitatively, the relatively slowly moving outer electron produces a quasi-static field at the inner electron given by l/rc2, and this field leads to the Stark effect in Ba+. The field allows the transitions to the n >n0Z and ,f 0 states and leads to shifts of the ionic energies. The presence of the njpn0f and n in0t resonances in the spectrum of Fig. 23.12 is quite evident. Camus et al. compared the shifts to those calculated in a fashion similar to a Bom-Oppenheimer calculation. With the outer electron frozen in place at ra they calculated the Ba+ energies, W,(rQ), and wavefunctions. They then added the energy W0(r0) to the normal screened coulomb potential seen by the outer electron. This procedure leads to a phase shift in the outer electron wavefunction... 

As we have shown, there is a clear correlation between the frequency shift of the stretching frequency of CO adsorbed at positively charged centers at the surfaces of non-transition metal oxides and halides and the electric held sensed by the molecule (Stark effect). This is the reason why CO is considered a specific and sensitive probe of the surface fields of ionic sohds. 

The first term of (3.289) represents a translational Stark effect. A molecule with a permanent dipole moment experiences a moving magnetic field as an electric field and hence shows an interaction the term could equally well be interpreted as a Zeeman effect. The second term represents the nuclear rotation and vibration Zeeman interactions we shall deal with this more fully below. The fourth term gives the interaction of the field with the orbital motion of the electrons and its small polarisation correction. The other terms are probably not important but are retained to preserve the gauge invariance of the Hamiltonian. For an ionic species (q 0) we have the additional translational term... 

Because of the short lifetime of ions in gaseous atmospheres, even at low pressure, gas-phase IR measurements are limited to adsorption of neutral molecules. Electrochemical applications of the IR method offer the interesting possibility of providing data on the adsorption properties of charged particles (Secs. 8 and 9). In the electrochemical environment the applied potential allows ionic adsorbates to be studied under energetically controllable conditions. Otherwise the electrochemical double layer offers exceptional conditions to investigate the Stark effect on vibrational transitions by setting tunable electric fields of the order of 10 V cm at the interface. This phenomenon will be discussed in Sec. 10. 

In this way Dexter showed how the quadratic (normal) Stark effect can produce an exponential edge at hcj < Eg if the field distribution is Gaussian. Dexter considers the ionic motion to be the source of the fields. The field intensity is proportional to the relative ion displacement q. Their distribution in thermal equilibrium is Gaussian. is determined by Eq. (4.13). It follows that F y T. By comparison of Eq. (4.20) with... 

Other exponential contributions to the relaxation rates of Ce +, Nd " " ions are explained naturally from the same standpoint. It seems reasonable to associate the contributions Tj (X exp(-A /kBT) with 4 = 18-19cm with an influence of the thulium ions of the first coordination sphere on the impurity lanthanide ions. An impurity ion distorts the crystal field at a distance of 3.7 A so strongly, that the thulium doublet state is split by approximately 20cm . In fact, there already appears a purely singlet Stark structure of energy levels in the low-symmetry crystal field. The distinction of 4 values for different lanthanide ions ean easily be coimected with the distinction of differences between the ionic radii of impurities and the ionic radius of the host thulium ion. The difference is... 

Nonadiabatic electronic transitions are of fundamental importance in chemistry. In particular, because a conical intersection (conical intersection) between two electronic states provides a very fast and efficient pathway for radiationless relaxation [117], there has been much interest in controlling transitions through a conical intersection. Indeed, several methods have already been proposed to control the dynamical processes associated with a conical intersection. One of these concerns the modification of electronic states involved in the conical intersection by environmental effects of polar solvents on the PES (potential energy hypersurface) through orientational fluctuations [6, 67, 68]. Another strategy is to apply a static electric field to shift the energy of a state of ionic character as in the Stark effect ]384, 482] (see Ref. ]403, 404] for the non-resonant dynamical Stark effect). More dynamical methods, which aim to suppress the transition either by preparing... 

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