The prospect of using the concept of a
universal reduced potential energy curve (RPC) for a broader class
of radial molecular functions is explored by performing appropriate
model calculations for the electric dipole moment functions of the
hydrogen halides HF, HCl, and HBr. The reduced radial functions of
the model systems, constructed from their best available theoretical
approximants, coincide so closely that they can be used as few-parameter
universal representations of functions available in the literature.
Given the mathematical nature of the problem addressed here, the results
are not limited to the functions studied but can be applied equally
well to all radial molecular functions that have similar shapes, such
as electric quadrupole moment and dipole polarizability functions.