Diamond Fayos J Journal of Solid State Chemistry 148 (1999) 278-285 Possible 3D carbon structures as progressive intermediates in graphite to diamond phase transition Note: mathematical model, phase: diam_cr44_ch _database_code_amcsd 0013986 4.591 4.591 4.591 90 90 90 Ia3 atom x y z C .1625 .1625 .1625