Aggregates of PCBM molecules: A computational study

- Equilibrium geometries and associated electronic and energetic properties of PCBMn (n = 1-5).
- The maximally stable structures identified tend to include a PCBM dimer motif.
- The significance of van-der-Waals effects for the prevailing bonding mechanism is demonstrated.
- OPLS force fields turn out to be effective stability predictors for PCBMn.
- The KS HOMO-LUMO gaps obtained may be useful to diagnose PCBM clustering in organic photocells.