Highly customized nonbonded potentials can be defined in OpenMM, allowing for future studies of complex foldamer systems. Coulombic interactions are not explicitly considered here at this time, as we are using a coarse-graining philosophy where Coulombic interactions can usually be treated as averaged out for neutral molecules. Throughout this work, reduced units for distance and energy are used: the base unit for length is the sigma parameter of the backbone bead (σ B ), and the base unit for energy is the epsilon parameter of the backbone bead (ε B ). The flow of data in the cg_openmm and analyze_foldamers Python packages is illustrated in Figure . First, the user specifies parameters, or ranges of parameters to scan, of the oligomer system. These include particle definitions, monomer topologies, oligomer length and residue sequence, bonded force field parameters, and nonbonded force field parameters. Initial particle coordinates may be either supplied from an existing file, or generated using a self-avoiding random walk algorithm. All of the above information about an oligomer system is stored in a CGModel class object. When initially constructed, the CGModel class generates an OpenMM topology object, which contains the model's bond, angle, and torsion definitions, and an OpenMM system object, which contains the model's force field parame-ters. The CGModel, in combination with the energy and trajectory coordinate files generated by OpenMM, is used to perform subsequent thermodynamic and structural analyses.