  This article is the second in the series and is devoted to the type G_2. The
work consists of two parts. In the first part we calculate the structure
constants of the complex simple Lie algebra of type G_2. All structure
constants are represented as functions of the structure constants corresponding
to extraspecial pairs. The results obtained are used to calculate the
commutator Chevalley formulas for [x_r(u),x_s(y)], when the sum r+s is a root.
  Further, in the second part there is a table of structure constants and
Chevalley commutator formulas in the special case, when all structure constants
corresponding to extraspecial pairs are positive.
