A parsable string giving one of the symmetry operations of the
space group in algebraic form. If W is a matrix representation
of the rotational part of the symmetry operation defined by the
positions and signs of x, y and z, and w is a column of
translations defined by the fractions, an equivalent position
X' is generated from a given position X by the equation
X' = WX + w
(Note: X is used to represent bold_italics_x in International
Tables for Crystallography Vol. A, Part 5)
When a list of symmetry operations is given, it must contain
a complete set of coordinate representatives which generates
all the operations of the space group by the addition of
all primitive translations of the space group. Such
representatives are to be found as the coordinates of
the general-equivalent position in International Tables for
Crystallography Vol. A (2002), to which it is necessary to
add any centring translations shown above the
general-equivalent position.
That is to say, it is necessary to list explicity all the
symmetry operations required to generate all the atoms in
the unit cell defined by the setting used.