Abstract
LONDON Royal Society, March 21. D. R. HABTBEE and W. HABTBEE: Self-consistent field, with exchange, for beryllium. Fock's equations for the self-consistent field of an atom, including exchange effects, have been completely solved numerically for the normal state of neutral Be. In connexion with the numerical calculations of energy values, a new check, depending on the direct calculation of the difference of energy values calculated using the solution of Fock's equations and using any other wave functions, is developed and applied. The inclusion of the exchange terms has a small but appreciable effect on the (1s) wave function, which becomes more like that for the Be++ ion, and a considerable effect on the (2s) wave function, which contracts, and also becomes smaller near the origin compared to its maximum value. These changes are qualitatively of a kind to bring calculated values of certain atomic properties into better accord with experiment. H. R. HULME, J. MCDOUGALL, R. A. BUCKINGHAM and R. H. FOWLEB: The photo-electric absorption of X-rays in heavy elements. A method is developed for finding the photo-electric absorption coefficient for the FC-shell, cr. The calculations are rigorous and are not subject to the restriction 137, where Z is the atomic number. Theoretically it is possible to apply the method for all values of h v, the energy of the quantum absorbed, but, as a considerable amount of numerical work is necessary, it is not practical for large values of hv/mc2. Values of a£ are given for 7v/me2 = 0-693 and 2-21 for elements with atomic numbers 26, 50 and 84. The values obtained do not differ much from those given by Hall, using a method which is discussed. His expression has therefore been used for GK in the region hv > 5mc2 and graphs have been constructed giving the photoelectric absorption per atom for various elements in the range hv > 0·7mc2 or 3-4 × 105 e.v. The values obtained for lead are in excellent agreement with the experimental results as given by L. H. Gray's empirical formula.
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Societies and Academies. Nature 135, 518–520 (1935). https://doi.org/10.1038/135518a0
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DOI: https://doi.org/10.1038/135518a0