Commonly used crystal materials include LiF ( lithium fluoride ), ADP ( ammonium dihydrogen phosphate ), Ge ( germanium ), graphite, InSb ( indium antimonide ), PE ( " tetrakis "-( hydroxymethyl )-methane : penta-erythritol ), KAP ( potassium hydrogen phthalate ), RbAP ( rubidium hydrogen phthalate ) and TlAP ( thallium ( I ) hydrogen phthalate ).
32.
Recently, novel liquid organogermanium precursors, such as isobutylgermane ( IBGe ) and tetrakis ( dimethylamino ) germane ( TDMAGe ) were developed and used in conjunction with the metalorganics of antimony and tellurium, such as tris-dimethylamino antimony ( TDMASb ) and di-isopropyl telluride ( DIPTe ) respectively, to grow GeSbTe and other chalcogenide films of very high purity by metalorganic chemical vapor deposition ( MOCVD ).
33.
Rather, there are three perpendicular 2-fold axes . " D " 2 is a subgroup of all the polyhedral symmetries ( see below ), and " D " 2 " h " is a subgroup of the polyhedral groups T h and O h . " D " 2 can occur in homotetramers such as Concanavalin A, in tetrahedral coordination compounds with four identical chiral ligands, or in a molecule such as tetrakis ( chlorofluoromethyl ) methane if all the chlorofluoromethyl groups have the same chirality.
