ASSESSMENT OF DENSITY-FUNCTIONAL METHODS FOR CALCULATING THERMOCHEMISTRIES OF SI-H-CL COMPOUNDS

The performance of the gradient-corrected BLYP density functional and the hybrid B3LYP functional has been studied in calculations of bond e nergies of Si-H-Cl containing molecules involved in thermal chemical v apor deposition processes of silicon. Calculated atomization energies using the BLYP and BSLYP functionals are in better agreement with expe riment (typically within 10 kcal/mol) compared to more computationally demanding methods such as MP4. Comparisons are also made with more ac curate theoretical methods including corrected MP4 approaches. While p redictions of thermochemical properties for second-row compounds from BLYP or B3LYP approaches are slightly less accurate than for first-row compounds, these techniques still represent a promising approach of o btaining theoretical estimates for thermochemical properties.