Molecular structures and infrared spectra of SiZrH4: A theoretical study

Molecular structures of the SiZrH4 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)ZrH2, trans-Si(μ-H)2ZrH2, cis-Si(μ-H)2ZrH2, and the triplet Si(μ-H)3ZrH are stable and comparable in energy. The energy of these four isomers is well below that of the Zr(3F2) + SiH4 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 SiH2 stretching modes are highly coupled with the two ZrH2 stretching modes. And such coupling cannot be removed by the full deuteration.