  HiRE-RNA is a simplified, coarse-grained RNA model for the prediction of
equilibrium configurations, dynamics and thermodynamics. Using a reduced set of
particles and detailed interactions accounting for base-pairing and stacking we
show that non-canonical and multiple base interactions are necessary to capture
the full physical behavior of complex RNAs. In this paper we give a full
account of the model and we present results on the folding, stability and free
energy surfaces of 16 systems with 12 to 76 nucleotides of increasingly complex
architectures, ranging from monomers to dimers, using a total of 850$\mu$s
simulation time.
