  We investigate the thermopower of a metal-molecule-metal junction taking into
account thermal effects on the junction. Based on analytical expressions and
numerical simulations we show that the thermoelectric potential reveals
valuable information on the mechanisms controlling the electron transfer
process, including coherent transmission and thermalized hopping. We also show
that at high temperatures the position of the Fermi energy relative to the
molecular states can be easily deduced from the thermoelectric potential.
Standard current-voltage measurements are insensitive to this information.
