Square-well pseudopotential

As we shall now explain, these four energies represent the square-well pseudopotential, the bottom, the centre, and the top of the m band, respectively, and thus give the first crude approximation to the properties of this band. 

Fig.4.1. Estimates of the extent (bottom B, top A) and position (centre C) of the s, p, and d bands of non-magnetic chromium obtained by the third-order expression (3.50), definitions (2.22), and the potential parameters in Table 4.1. Expression (3.50) spans only the square-well pseudopotentials V for the s and p bands, i.e. Vd is outside the energy window...

Fig. 13. An overview of the electronic structure of the trivalent lanthanides, evaluated at a common Wigner-Seitz radius of 3.75 au (after Skriver 1983b). The bottom, B, top, A, centre, C and square-well pseudopotential, K, are plotted, and F(S) is the potential and the exchange-correlation density at the sphere boundary. The Fermi energy is labelled by p.

Figure 5.8 The pseudopotential proposed by Heine and Abarenkov that is a square-well model potential with value A inside a cutoff radius r .

Focusing of ions in curved FAIMS (4.3.1) means a pseudopotential bottoming near the gap median. Devices using such wells to guide or trap ions (e.g., quadrupole filters or traps and electrodynamic funnels) have finite charge capacity or saturation current (/sat) the Coulomb potential scales as the charge density squared and, above some density, exceeds the well depth and expels excess ions from the device. Simulations... 

Figure 1.15 Comparison of the electron affinity within the spheroidal jellium model plus SIC and various experimental results (circles [44], triangles [45], squares [46]). For N = 30 theory predicts two isomers (prolate and oblate), which are nearly degenerate. But both do have different affinities and in the beam the signal will come from those clusters having the lower affinities (connected by dashed lines). Clearly, shell effects are very pronounced. Qualitatively theory and experiment agree rather well. In order to achieve quantitative agreement one has to introduce pseudopotential perturbation theory as sketched above. Reproduced by permission of Springer Verlag...

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