  A general relation for the dependence of nearest neighbor degree correlations
on degree is derived. Dependence of local clustering on degree is shown to be
the sole determining factor of assortative versus disassortative mixing in
networks. The characteristics of networks derived from spatial atomic/molecular
systems exemplified by self-organized residue networks and block copolymers,
atomic clusters and well-compressed polymeric melts are studied. Distributions
of statistical properties of the networks are presented. For these
densely-packed systems, assortative mixing in the network construction is found
to apply, and conditions are derived for a simple linear dependence. Together,
these measures (i) reveal patterns that are common to close-packed clusters of
atoms/molecules, (ii) identify the type of surface effects prominent in
different systems, and (iii) associate fingerprints that may be used to
classify networks with varying types of correlations.
