Continuous transformations of C60 crystals: polymorphs, polymers, and the ideal strength of fullerites.

Application of pressure is a versatile method to tailor the properties of organic semiconductors. For example, it is known that high pressure can transform C60 face-centred-cubic (FCC) crystals to polymer structures with inter-molecular bonds. Here we use first-principles calculations to describe continuous crystalline transformation paths that include the FCC and polymer structures as distinct local energy minima. In addition to analysing the atomic-scale details of polymerization, we obtain the ideal strength of FCC-C60, identify metastable C60 crystalline polymorphs, and characterize their electronic properties-all key features for the performance of C60 crystals in organic electronic devices.