Screening function Moliere

In conclusion, the repulsive interactions arise from both a screened coulomb repulsion between nuclei, and from the overlap of closed inner shells. The former interaction can be effectively described by a bare coulomb repulsion multiplied by a screening function. The Moliere function, Eq. (5), with an adjustable screening length provides an adequate representation for most situations. The latter interaction is well described by an exponential decay of the form of a Bom-Mayer function. Furthermore, due to the spherical nature of the closed atomic orbitals and the coulomb interaction, the repulsive forces can often be well described by pair-additive potentials. Both interactions may be combined either by using functions which reduce to each interaction in the correct limits, or by splining the two forms at an appropriate interatomic distance . 

Simple mathematical expressions have been developed for the Thomas-Fermi, Bohr, Lenz-Jensen, and Moliere screening functions. Several forms exist for the Thomas-Fermi model. The earliest and best known of these is the Sommerfeld asymptotic form,... 

The Moliere form of the screening function is composed of three exponentials ... 

The most widely used screening function is that due to Moliere [206] using Thomas-Fermi statistics, which is approximated by... 

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