  The parity (P) and time-reversal (T) odd coupling constant associated with
the tensor-pseudotensor (T-PT) electron-nucleus interaction and the nuclear
Schiff moment (NSM) have been determined by combining the result of the
measurement of the electric dipole moment (EDM) of ^{129}Xe atom and
calculations based on the relativistic coupled-cluster (RCC) theory.
Calculations using various relativistic many-body methods have been performed
at different levels of approximation and their accuracies are estimated by
comparing the results of the calculated dipole polarizability of the ground
state of the above atom with its most precise available experimental data. The
non-linear terms that arise in the RCC theory at the singles and doubles
approximation were found to be crucial for achieving high accuracy in the
calculations. Our results for the ^{129}Xe EDM due to the odd T-PT interaction
and the NSM are, respectively, d_A=0.501 x 10^{-20} C_T <\sigma_N > |e|cm and
d_A=0.336 x 10^{-17} S/(|e| fm^3) |e|cm. These results in combination with the
future EDM measurements in atomic Xe could provide the most accurate limits for
the T-PT coupling constant and NSM.
