  Mutual information and information entropies in momentum space are proposed
as measures of the non-local aspects of information. Singlet and triplet state
members of the helium isoelectronic series are employed to examine Coulomb and
Fermi correlation, and their manifestations, in both the position and momentum
space mutual information measures. The triplet state measures exemplify that
the magnitude of the spatial correlations relative to the momentum
correlations, depends on, and may be controlled by the strength of the
electronic correlation. Examination of one and two-electron Shannon entropies
in the triplet state series yields a crossover point, which is characterized by
a localized momentum density. The mutual information density in momentum space
illustrates that this localization is accompanied by strong correlation at
small values of $p$.
