Nonrelativistic Wentzel-Kramers-Brillouin eigenvalues of the Thomas-Fermi neutral-atom potential in the large-atomic-number limit

1985 ◽  
Vol 32 (3) ◽  
pp. 1322-1327 ◽  
Author(s):  
G. Senatore ◽  
N. H. March
Keyword(s):  
Atomic Number ◽  
Neutral Atom ◽  
Thomas Fermi ◽  
Large Atomic Number ◽  
Atom Potential

scholarly journals ATOMS IN THE ANIONIC DOMAIN, Z < N

2013 ◽  
Vol 27 (24) ◽  
pp. 1350178 ◽  
Author(s):  
GABRIEL GIL ◽  
AUGUSTO GONZALEZ
Keyword(s):  
Ionization Potential ◽  
Neutral Atom ◽  
Nuclear Charge ◽  
Instability Threshold ◽  
The Other ◽  
Covalent Radius ◽  
Energy Curve ◽  
Fermi Theory ◽  
Thomas Fermi ◽  
Linear Behavior

We study atoms with N electrons, and nuclear charge Z. It is well known that the cationic regime, Z > N, is qualitatively described by Thomas–Fermi theory. The anionic regime, Z < N, on the other hand, is characterized by an instability threshold at Zc ≲ N-1, below which the atom spontaneously emits an electron. We compute the slope of the energy curve at Z = N - 1 by means of a simple model that depends on the electron affinity and the covalent radius of the neutral atom with N - 1 electrons. This slope is used in order to estimate Zc, which is compared with previous numerical results. Extrapolation of the linear behavior in the opposite direction, up to Z = N, allows us to estimate the ionization potential of the atom with N electrons. The fact that the obtained ionization potentials are qualitatively correct is an indication that, with regard to certain properties, neutral atoms are closer to the anionic instability threshold than they are to the Thomas–Fermi, large Z, region. A regularized series is written for the ionization potential that fits both, the large Z and Z → Zc limits.

Asymptotic Relations between the Thomas—Fermi—Dirac and Thomas—Fermi Atom Models. I. Case of Low Atomic Number

1967 ◽  
Vol 47 (3) ◽  
pp. 1029-1035 ◽  
Author(s):  
J. J. Gilvarry ◽  
R. E. Hartle ◽  
N. H. March
Keyword(s):  
Atomic Number ◽  
Thomas Fermi

scholarly journals Considerations of image contrast in Electron Microscopy of objects composed of low atomic number

1962 ◽  
Vol 17 (11) ◽  
pp. 728-731
Author(s):  
M. L. De
Keyword(s):  
Electron Microscopy ◽  
Atomic Number ◽  
Electron Scattering ◽  
Image Contrast ◽  
Thomas Fermi ◽  
Mass Thickness ◽  
Atom Model

Defects of the electron scattering formula based on Thomas-Fermi atom model and of Lei segang's formula, are first briefly discussed in relation to image contrast problem in Electron Microscopy. A few aspects of the electron scattering formula of Lenz are then considered particularly for dealing with elements of low atomic number. From a consideration of this formula it is shown that the image contrast of a given mass thickness of object is liable to be dependent on the atomic number of the object.

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