Framework reconstruction between hR8 and cI16 germaniums: A molecular dynamics study†
Using molecular dynamics simulations and a Density Functional based Tight Binding method, the metastable germanium allotropes hR8 and cI16 are shown to interconvert by means of two sets of quasi-1D chains. The first set hosts sequences of SN2 inversions of Ge tetrahedral centers, and represents the activated step. The second set does not imply any reconstruction, but assists the first one in propagating the reconstruction. The overall process is commenced by bond nucleation, followed by chain formation and reconstruction into either structure. A novel intermediate metastable phase is visited in the process. Elementary steps of chemical reactivity are accessible due to the appropriate time and spatial resolution of the methods used. This paves the way for a chemical understanding of structure reconstruction and metastable phase formation in solid materials.