  The standard infinite-volume definition of connected correlation function and
particle mass in the 3-state Potts model can be implemented in Monte Carlo
simulations by using C-periodic spatial boundary conditions. This avoids both
the breaking of translation invariance (cold wall b.c.) and the phase-dependent
and thus possibly biased evaluation of data (periodic boundary cconditions).
The numerical feasibility of the standard definitions is demonstrated by sample
computations on a 24*24*48 lattice.
