Calibration and comparison of the Gaussian-2, complete basis set, and density functional methods for computational thermochemistry

We have reexamined several high-accuracy Gaussian-2, complete basis set and density functional methods for computational thermochemistry (in order of increasing speed): G2, G2(MP2), CBS-Q, G2(MP2,SVP), CBS-q, CBS-4, and B3LYP/6-311+G(3df,2p). We have employed ΔfH2980 for the “extended G2 neutral test set” for this comparison. Several errors in previous studies have been corrected and experimental spin-orbit interactions have been included in all calculated atomic energies. The mean absolute deviations from experiment are 1.43, 1.76, 1.19, 1.64, 2.34, 2.66, and 3.43 kcal/mol, respectively. The maximum deviations from experiment are 10.6, 8.8, 8.1, 9.4, 11.4, 12.9, and 24.1 kcal/mol respectively. The species responsible for these maximum errors are in order: SiF4, SiF4, Cl2C=CCl2, F2C=CF2, ClF3, ClF3, and SiCl4. All seven methods have relatively large errors for bonds to halogens, but these errors are sufficiently systematic to benefit from empirical corrections. After a discussion of ill conditioning in th...

[1]  B. Ruscic,et al.  On the heat of formation of carbonyl fluoride, CF2O , 1996 .

[2]  Krishnan Raghavachari,et al.  ASSESSMENT OF COMPLETE BASIS SET METHODS FOR CALCULATION OF ENTHALPIES OF FORMATION , 1998 .

[3]  G. A. Petersson,et al.  A Comparison of Model Chemistries , 1995 .

[4]  J. Pedley.  Thermochemical data and structures of organic compounds , 1994 .

[5]  Charles W. Bauschlicher,et al.  A comparison of the accuracy of different functionals , 1995 .

[6]  J. Montgomery,et al.  Ab initio calculation of the heats of formation of CF3OH and CF2O , 1994 .

[7]  G. Herzberg.  Molecular Spectra and Molecular Structure IV. Constants of Diatomic Molecules , 1939 .

[8]  Kenneth R. Hall,et al.  Thermodynamic Properties of Key Organic Oxygen Compounds in the Carbon Range C1 to C4. Part 1. Properties of Condensed Phases , 1985 .

[9]  John A. Montgomery,et al.  A complete basis set model chemistry. V. Extensions to six or more heavy atoms , 1996 .

[10]  V. P. Kolesov.  Thermochemistry of Halogenomethanes , 1978 .

[11]  Leo Radom,et al.  Molecular orbital theory of the electronic structure of organic compounds. V. Molecular theory of bond separation , 1970 .

[12]  Eileen P. Clifford,et al.  Properties of Diazocarbene (CNN) and the Diazomethyl Radical (HCNN) via Ion Chemistry and Spectroscopy , 1998 .

[13]  L. Curtiss,et al.  Assessment of Gaussian-2 and density functional theories for the computation of enthalpies of formation , 1997 .

[14]  H. Schaefer,et al.  Thermochemistry of CHn, SiHn (n=0–4), and the cations SiH+, SiH2+, and SiH3+: A converged quantum mechanical approach , 1992 .

[15]  Æleen Frisch,et al.  Exploring chemistry with electronic structure methods , 1996 .

[16]  G. Herzberg,et al.  Molecular Spectra and Molecular Structure , 1992 .

[17]  A. Becke,et al.  Density-functional exchange-energy approximation with correct asymptotic behavior. , 1988, Physical review. A, General physics.

[18]  A. Becke.  Density-functional thermochemistry. III. The role of exact exchange , 1993 .

[19]  M. Zachariah,et al.  Halon Thermochemistry: Ab Initio Calculations of the Enthalpies of Formation of Fluoromethanes , 1995 .

[20]  Krishnan Raghavachari,et al.  Gaussian-2 theory for molecular energies of first- and second-row compounds , 1991 .

[21]  Krishnan Raghavachari,et al.  Accurate thermochemistry for larger molecules : gaussian-2 theory with bond separation energies. , 1997 .

[22]  Parr,et al.  Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. , 1988, Physical review. B, Condensed matter.

[23]  Leo Radom,et al.  Gaussian‐2 (G2) theory: Reduced basis set requirements , 1996 .

[24]  Krishnan Raghavachari,et al.  Gaussian-2 theory using reduced Moller--Plesset orders , 1993 .