  We present a Hamiltonian Monte Carlo study of doped perylene
$\mathrm{C}_{20}\mathrm{H}_{12}$ described with the Hubbard model. Doped
perylene can be used for organic light-emitting diodes (OLEDs) or as acceptor
material in organic solar cells. Therefore, central to this study is a scan
over charge chemical potential. A variational basis of operators allows for the
extraction of the single-particle spectrum through a mostly automatic fitting
procedure. Finite chemical potential simulations suffer from a sign problem
which we ameliorate through contour deformation. The on-site interaction is
kept at $U/\kappa = 2$. Discretization effects are handled through a continuum
limit extrapolation. Our first-principles calculation shows significant
deviation from non-interacting results especially at large chemical potentials.
