Body center tetragonal Pseudo-diamond C20: Crystal Chemistry and first principles Investigations

Extending the investigation of the graphite to diamond G2Dlike changes of carbon crystal systems implying 2D planar trigonal C(sp2)like paving to 3D tetrahedral sp3 to 3D trigonal to tetrahedral transformation, original body centered tetragonal BCT C20 allotrope with dia (diamond) topology was devised from crystal chemistry rationale and demonstrated to behave like diamond for all the physical properties. The investigations were based on crystal chemistry and first principles investigations within the Density Functional theory with comparisons to available experimental observations. Holistic assessment of the results let assign BCT C20 a pseudo-diamond label.