On the additivity of basis set effects in some simple fluorine containing systems

✍ Scribed by Edgar W. Ignacio; H. Bernhard Schlegel

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 705 KB
• Volume: 12
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540120613

✦ Synopsis

• Fwere used as simple test cases to assess the additivity of basis set effects on reaction energetics computed at the MP4 level. The 6- 31G and 6-311G basis sets were augmented with 1, 2, and 3 sets of polarization functions, higher angular momentum polarization functions, and diffuse functions (27 basis sets from 6-31G(d, p ) to 6-31 ++ G(3df, 3pd) and likewise for the 6311G series). For both series substantial nonadditivity was found between diffuse functions on the heavy atom and multiple polarization functions (e.g., 6-31 + G(3d, 3p) vs. 6-31 + G(d, p ) and 631G(3d, 3p)). For the 6-311G series there is an extra nonadditivity between d functions on hydrogen and multiple polarization functions. Provided that these interactions are taken into account, the remaining basis set effects are additive to within r0.5 kcal/mol for the reactions considered. Large basis set MP4 calculations can also be estimated to within k0.5 kcal/mol using MP2 calculations, est. EMp4(6-31 ++ G(3df, 3pd)) = EMP4(6-31G(d, p ) ) + EM,(6-31 ++ G(3dJ 3pd)) -EM,(6-31G(d, p ) ) or EMp4(6-31 + G(d, p ) + EM,(6-31 ++ G(3dJ 3pd)) -EMp2(6-31 + G(d, p ) ) and likewise for the 6-311G series.