Vacuum double-well potential

The electronic ground state of this non-polar species is still of interest because classical rotationally resolving methods are difficult to apply. Bermejo et al. [02Ber] report on high-resolution rovibrational Raman spectra of Cl2, Cl2, and Cl Cl, and their spectroscopic constants for the vibrational states v = 0,1,2. Wang et al. [98Wan] have measured rotationally resolved vacuum ultraviolet REMPI detected laser spectra of the Cl2 1 <— X transition, and obtained rotational constants of levels loealized in the double-well potential of... 

FIGURE 3.11 The potential of Eq. (3.464) with +/<, in dashed curve and with -fi=x on continuous curve, illustrating the symmetry breaking of the parabolic (upper curve) to double well potential (lower curve) that includes also the negative (vacuum) quantum states (Putz, 2008d). 

These measurements have verified that the work function of an electrode, emersed with the double layer intact, depends only on the electrode potential and not on the electrode material or the state of the electrode (oxidized or covered with submonolayer amounts of a metal) [20]. Work function measurements on emersed electrodes do not serve the same purpose as in surface science investigations of the solid vacuum interface. At the electrochemical interface, any change of the work function by adsorption is compensated by a rearrangement of the electrochemical double layer in order to keep the applied potential i.e. overall work function, constant. Work function measurements, however, could well be used as a probe for the quality of the emersion process. Provided the accuracy of the measurement is good enough, a combination of electrochemical and UPS measurements may lead to a determination of the components of equation (4). 

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