We report the results of electronic structure coupled to molecular dynamics simulations on organic polymers subject to a temperature gradient at low temperature regimes. The temperature gradient is introduced using a Langevin-type dynamics corrected for quantum effects, which are very important in these systems. Under this condition we were able to determine that in these no-impurity systems the Seebeck coefficient is in the range of 1-3 mu V/K. These results are in good agreement with reported experimental results under the same low-temperature conditions.