Premium
A theoretical study of bond energies in model Si–H–Cl molecules using density functional approaches for representing Si surface chemistry
Author(s) -
Boehm Randall C.,
Kress Joel D.,
Martin Richard L.,
Hay P. Jeffrey
Publication year - 1997
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/(sici)1096-987x(199712)18:16<2075::aid-jcc11>3.0.co;2-n
Subject(s) - chemistry , computational chemistry , density functional theory , bond length , bond energy , bond order , molecule , single bond , potential energy surface , valence (chemistry) , basis set , ab initio , sextuple bond , group (periodic table) , organic chemistry
The reliability of density functional theory (DFT) methods for calculating Si(SINGLE BOND)2H, Si(SINGLE BOND)Cl, and Si(SINGLE BOND)Si bond energies is examined in reactions involving molecules and small clusters representing various surface sites appropriate for Si surface chemistry. Results are presented for systematic studies using a valence double‐zeta polarization basis for both all‐electron calculations and valence–electron calculations employing effective core potentials (ECPs). All‐electron DFT results are comparable to much more demanding MP4, G2, and MC–SCF–CI calculations for computed bond energies. Whereas the use of ECPs introduces systematic energy differences of ca. 3–5 kcal/mol compared to AE results, depending on the type of bond involved, the use of ECPs for carrying out calculations on larger clusters is discussed where AE calculations become more computationally demanding. The convergence of Si bond energies as a function of replacing hydrogens with silyl groups is examined. In constructing models to describe etching processes involving Cl species on Si surfaces, the need for incorporating differences in thermochemistries for one‐, two‐, and three‐coordinate Si surface sites is emphasized. Comparisons of semiempirical approaches for thermochemistries of Si‐containing species find these methods somewhat less reliable for obtaining reliable bond energies compared to computationally more demanding DFT and ab initio correlated models. © 1997 John Wiley & Sons, Inc. J Comput Chem 18 : 2075–2085, 1997