GAUSSIAN code

Theoretical chemistry at York University was strengthened in the 1990s with the appointments of Bill Pietro in 1991 and Rene Fournier in 1996. Pietro wrote part of the Gaussian code as a graduate student and several modules of SPARTAN while an assistant professor at the University of Wisconsin. While he was in Madison he developed a research program based on molecular electronic devices.236 He expanded his interests to several facets of molecular electronics, including molecular electroluminescent materials, molecular electronic devices (diodes, switches, and sensors), and functionalized semiconductor nanoclusters.237 These new materials not only are scientifically very exciting, but they offer the possibility of revolutionary impact on the future of the electronics industry. 

We also performed a G2 procedure as implemented in the Gaussian code for all of the structures involved. Differently from the standard G2 procedure, we used the ZPVE values obtained with MP2 rather than HF for anharmonicity corrections. 

All calculations on the isolated and the PCM solvated systems have been performed using the Gaussian code [39] while the DPM calculations have been performed using the development version of the Dalton Quantum Chemistry Program [40],... 

QCPE distributes, for example, an early version of the GAUSSIAN code, GAUSSIAN70.26... 

All calculations were carried out with the Gaussian code, using a recent hybrid Kohn-Sham/Hartree-Fock (KS/HF) model hereafter referred to as PBEO. This approach is obtained casting the PBE exchange and correlation functional in a hybrid scheme HF/DFT, where the HF exchange ratio (1 4) is fixed apriorf . ... 

The main codes for periodic DFT calculations differ by the choice of basis sets. There are three possibilities atomic orbitals (CRYSTAL, SIESTA, GAUSSIAN codes), plane waves (Vienna ab initio simulation package (VASP), CASTEP, DACAPO, CPMD, Quantum-ESPRESSO codes), or both with a partition of the space between atomic spheres and intermediate regions (APW, LMTO, KKR, WIEN2K codes). We will shortly describe the advantage and disadvantage of the two extreme choices taking CRYSTAL and VASP as representative codes. 

Theoretical studies have been based on ab-initio molecular orbital calculations performed using either the Gaussian 86 code or, earlier, Gaussian codes on a Cray 1 Computer. The majority of calculations employed a modestly sized basis set (6-31G)to save computational time but a few have been carried out using a larger (6-311G ) basis set and using Moller-Plesset (MP) many-body perturbation theory to second or fourth order. 

GAUSSIAN code [418]. It was demonstrated for molecular systems that the HSE03 hybrid functional delivers results (bond lengths, atomization energies, ionization potentials, electron affinities, enthalpies of formation, vibrational frequencies), that are comparable in accuracy to the nonempirical PBEO hybrid functional [409,411,412]. 

Both results obtained with a cluster (CL) and a periodic (PBC) Ti02 model are reported. PBE/DZ (TZ)VP data were obtained by the ADF code and PBE/PWs by the CP code PBE/6-311G and B3LYP/6-311G have been obtained by the Gaussian code... 

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