  We study a large number of physically-plausible arrangements of chromophores,
generated via a computational method involving stochastic real-space
transformations of a naturally occurring `reference' structure, illustrating
our methodology using the well-studied Fenna-Matthews-Olson complex (FMO). To
explore the idea that the natural structure has been tuned for efficient energy
transport we use an atomic transition charge method to calculate the excitonic
couplings of each generated structure and a Lindblad master equation to study
the quantum transport of an exciton from a `source' to a `drain' chromophore.
We find significant correlations between structure and transport efficiency:
High-performing structures tend to be more compact and, among those, the best
structures display a certain orientation of the chromophores, particularly the
chromophore closest to the source-to-drain vector. We conclude that, subject to
reasonable, physically-motivated constraints, the FMO complex is highly attuned
to the purpose of energy transport, partly by exploiting these structural
motifs.
