The Atomic Nucleus

• As molecules and heavy atoms get invoked for studies of fundamental interactions and properties, the demand for more accurate descriptions of the wavefunction within and close to the nucleus grow more stringent. With the generally increasing precision of quantum chemistry calculations, the simple point-nucleus approximation, resulting in the well-known Z=r potential, is no longer completely adequate. The inadequacy becomes more and more evident as quantum chemistry takes on the challenge of molecules including heavy, or even superheavy, atoms: For large Z, the behaviour close to the nucleus becomes too singular for a point nuclear charge, and for the|still hypothetical|case of Z > 137, the Dirac equation breaks down. For finite nuclear distributions, the possible range extends much further. Many properties depend on details of the nuclear structure. What are the alternatives for the nuclear distributions used in calculations? What are their advantages and disadvantages from a computational point of view? How should calculated results be presented in order to make possible meaningful comparisons between results obtained using different approaches? How much is known experimentally and how is that information best included in the calculations? These are a few of the questions addressed in this chapter. This chapter focuses mainly on the distribution of charge, which, however influences also other properties.

Ämnesord

NATURVETENSKAP  -- Fysik -- Annan fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Other Physics Topics (hsv//eng)

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

NATURVETENSKAP  -- Matematik -- Beräkningsmatematik (hsv//swe)

NATURAL SCIENCES  -- Mathematics -- Computational Mathematics (hsv//eng)

Nyckelord

nuclear distrbution

isotope shift

Fermi distribution

Bohr-Weisskopf

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