  This study deals with cubic crystals where the contents of the simple cubic
unit cells are close to n$\times$n$\times$n-bcc sublattices ($n$ = 2: diamond-
and zinc-blende type, $n$ = 3: $\gamma$-brasses). First-principle results on
the electronic structure are obtained from augmented LMTO-ASA calculations and
interpreted within a VEC-based Hume-Rothery concept which employs joined
planar-radial interferences to treat interference and hybridization on the same
footing. We show that the charge redistribution supports enhanced electronic
interference which causes the band energy to decrease. Several topics are
included such as stabilizing networks, hardness and $s$-to-$p$ transfer,
co-operation of interferences, interplay between local radial order and global
planar order, electron-per-atom ratio, and the comparison with recent
FLAPW-based results.
