  Explicit expressions for inverse of Young's modulus E, inverse of shear
modulus G, and Poisson's ratio for cubic media are considered. All these
characteristics of elastic media depend on three components of the compliance
tensor S, and on direction cosines of mutually perpendicular vectors m and n
with fourfold symmetry axes. These characteristics are studied for all
mechanically stable cubic materials for vectors n belonging to the irreducible
body angle subtended by three cubic high symmetry directions [001], [111], and
[110]. Regions in the stability triangle of in which cubic elastic materials
are completely auxetic, non-auxetic, and auxetic are established. Several
intermediate-valence compounds belonging to the region of complete auxecity are
indicated. The extreme properties of E^{-1}, G^{-1} and Poisson ratio
established by Hayes and Shuvalov are confirmed.
