Molecular structures and infrared spectra of SiZrH4: A theoretical study

Abstract Molecular structures of the SiZrH 4 complex were investigated at BPW91, BPW91/IEF-PCM, B3LYP, and MP2 levels of theory with substantial basis sets. Relative stability of the stable conformers is fairly dependent on the methods, solvent effects, and zero-point energy corrections. All the four levels of calculations indicated that the singlet HSi( μ -H)ZrH 2 , trans -Si( μ -H) 2 ZrH 2 , cis -Si( μ -H) 2 ZrH 2 , and the triplet Si( μ -H) 3 ZrH are stable and comparable in energy. The energy of these four isomers is well below that of the Zr( 3 F 2 ) + SiH 4 system. The trans -dibridged, rather than the tribridged, isomer was always predicted to be the most stable one by all the four levels of calculations. For the two dibridged isomers, the two SiH 2 stretching modes are highly coupled with the two ZrH 2 stretching modes. And such coupling cannot be removed by the full deuteration.