We have theoretically investigated the mechanism of the pressure-induced reconstructive zinc-blende to rocksalt phase transition in SiC. We obtained 925 possible transition pathways ͑TPs͒ using a group-theoretical analysis method. This extensive survey of possible TPs is a significant feature which distinguishes this study from previous studies. Of these 925 TPs, we identified eight which have the lowest enthalpy barriers, based on first-principles electronic structure calculations. These eight TPs share a common underlying mechanism: bilayer sliding of ͑111͒ planes such that local bonding evolves from tetrahedral to octahedral without breaking any bonds. This mechanism may be applicable to other related transitions involving similar bonding changes.

We have theoretically investigated the mechanism of the reconstructive wurtzite-to-rocksalt phase transition. Using COMSUBS, we found five different bond-preserving transitions pathways. These transition paths share a common underlying mechanism: bilayer sliding of ͑010͒ hexagonal planes along the ͓100͔ hexagonal directions.

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