Gaussian-4 theory

The Gaussian-4 theory (G4 theory) for the calculation of energies of compounds containing first- (Li-F), second- (Na-Cl), and third-row main group (K, Ca, and Ga-Kr) atoms is presented. This theoretical procedure is the fourth in the Gaussian-n series of quantum chemical methods based on a sequence of single point energy calculations. The G4 theory modifies the Gaussian-3 (G3) theory in five ways. First, an extrapolation procedure is used to obtain the Hartree-Fock limit for inclusion in the total energy calculation. Second, the d-polarization sets are increased to 3d on the first-row atoms and to 4d on the second-row atoms, with reoptimization of the exponents for the latter. Third, the QCISD(T) method is…

• NS
  National Science Foundation

  Award: 0616737
• UD
  U.S. Department of Energy

  Awards: 06CH11357, DE-AC-02-06CH11357
• DO
  Division of Chemistry
• AN
  Argonne National Laboratory

  Awards: 06CH11357, DE-AC-02-06CH11357