  Two-dimensional electronic spectra (2DES) provide unique ways to track the
energy transfer dynamics in light-harvesting complexes. The interpretation of
the peaks and structures found in experimentally recorded 2DES is often not
straightforward, since several processes are imaged simultaneously. The choice
of specific pulse polarization sequences helps to disentangle the sometimes
convoluted spectra, but brings along other disturbances. We show by detailed
theoretical calculations how 2DES of the Fenna-Matthews-Olson complex are
affected by rotational and conformational disorder of the chromophores.
