The change from 2D Graphitic-like carbon to 3D Diamond-like structure (G2D) involves physical and chemical mechanisms that have been studied both experimentally and at different levels of modeling over the last 25 years. In 1999, Fayos showed that successive contractions of graphite in different directions, accompanied with C(sp 2 ) to C(sp 3 ) hybridization change simulate G2D phase transition . Recently we proposed to broaden the G2D-like changes approach to be initiated by i-the puckering of the atomic planar G layers by driving selected carbon atoms into off-plane positions on the one hand, and ii-a rationalized interlayer insertion of extra C to enforce the 3D structure, on the other hand (cf. and therein cited works). Also, the simultaneous presence of the two types of hybridizations was reported for a series of carbon allotropes characterized with high hardness . Both last works were based on crystal engineering investigations and supported by quantum mechanics calculations within the Density Functional Theory (DFT) .