PC Gamess

The molecular structure and vibrational frequencies for all the considered hydrof-ullerenes were calculated in terms of the density functional theory at the B3LYP/6-31G theory level using the PC GAMESS/Firefly software (Schmidt et al. 1993 Granovsky 2009). The atomic masses were taken from Loss (2003). 

Granovsky AA (2009) PC GAMESS/Firefly version 7.1.F, www http //classic.chem.msu.su/gran/ gamess/index.html... 

Level shifting [15] and DIIS [16] techniques have been adopted to increase convergence performance [17]. The SCF-MI option is also incorporated in the particularly efficient PC GAMESS version [18] of the GAMESS-US quantum chemistry package. 

The geometrical parameters of equilibrium configurations of small fullerenes isolated molecules C , their dimers (Cn)2 and cuban-like clusters(Cn)8 are obtained for n = 20, 24, 28, 32. The Cuban like clusters can be considered as fragments of polymerized crystal structures with simple cubic symmetry. Total energy, heat of formation, energies of HOMO and LUMO orbitals, density of one-electron states (DOS) are determined for equilibrium configurations of all these objects. All the computations are performed by help of pocket PC Gamess in frames of optimized semi-empirical PM3-basis [4-5],... 

Abstract. Equilibrium configurations, total energies, heats of formation, energies of HOMO and LUMO states, densities of one-electron states (DOS) and IR spectra of CNTs T-junctions of the various types are calculated by employing of PC Gamess version of semi-empirical quantum chemistry PM3-method. 

To extract Hessian (matrix of second derivatives of total energy on atoms coordinates) from the results of calculations performed in frames of PC Gamess version of PM3-method one can compute the frequencies of all self vibration modes as good as intensities of infrared (IR) spectra of T-junctions and compare this spectra with computed IR spectra of the ideal nanotubes. 

Quantum chemistry computations based on employing of PC Gamess version of semi-empirical PM3-method [1-2] allows to define equilibrium configuration and calculate electronic structure of some of the simplest Y-junctions of carbon nanotubes, which have slang name twig . On the place of nanotubes conjunction defective cycles appear. Their type, number and mutual displacement can be enough various even in comparatively simple cases. Only the part of obtained results is presented here. 

The calculations were performed by the ab initio density functional method with the B3LYP1 potential and MINI/EPRII basis. The software package PC GAMESS [4] was used. The calculations were performed for a triplet ground state. The cluster charge was set to -1 in all the cases considered. 

The density functional theory (DFT) was employed for calculations using the B3LYP1 functional with the MINI/EPRII (C, N), TZV (Ni) basis sets. The standard PC GAMESS [11] software was used. 

The aim of this work is a study of electronic stmcture of molecules a-cyclopropyl-p-izopropylstyrene, a-cyclopropyl-p-izopropylstyrene, a-cyclopropyl-2,4-dimethyl styrene, a-cyclopropyl-p-ftoistyrene [1] and theoretical estimation its acid power by quantum-chemical method MNDO. The calculation was done with optimization of all parameters by standard gradient method built-in in PC GAMESS [2]. The calculation was executed in approach the insulated molecule in gas phase. Program MacMolPlt was used for visual presentation of the model of the molecule [3]. 

Fungal cell wall simulated as two chitin dimers. To obtain the optimized geometry of ground state, several DFT codes were used, including PC GAMESS, SIESTA and ABINIT (Fig. I of Section 5.4). 

PC GAMESS Firefly v7.1 programs [14] were used in carrying out quantum and chemical calculations. Searching for the equilibrium geometry of the transition states was carried out by MP2(fc)/6-31G(d) [15-17] approximation. Verification of the transition state was made by calculating vibrational parameters for the obtained transition state geometry with the... 

MOPAC-97 and PC GAMESS v7.1 programs [9] were used in carrying out quantum and chemical calculations. 

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