  The 1-loop computation of the processes $\tchi_i \tchi_j \to \gamma Z$ has
been performed at an arbitrary c.m. energy for any pair of MSSM neutralinos. As
an application suitable for Dark Matter (DM) searches, the
neutralino-neutralino annihilation is studied at the limiting case of vanishing
relative velocity, describing the present DM distribution in the galactic halo;
and at a relative velocity of about 0.5, determining the neutralino relic
density contributions. The most useful situation is obviously for $i=j=1$, but
the case of non-identical neutralinos may also be useful in some corners of the
parameter space. Our results are contained in the FORTRAN code PLATONdmgZ,
applying to any set of real MSSM parameters. Numerical results are also
presented for a sample of 6 MSSM models, describing the various possible
neutralino properties. A comparison with other existing works is also made.
