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Showing papers in "Chemical Physics Letters in 1993"


Journal ArticleDOI
TL;DR: In this paper, a set of seven-component f-type polarization functions has been optimized for use with the pseudo-potentials of Hay and Wadt at the CISD level of theory for the transition metals ScCu, YAg, LaAu in the energetically lowest-lying s 1 d n electronic state.

1,927 citations


Journal ArticleDOI
TL;DR: Three-center approximations to the four-center integrals occurring in ab initio LCAO calculations are investigated in this paper, where significant gains in computer time can be obtained without sacrificing accuracy, if a suitable expansion basis is chosen.

1,474 citations


Journal ArticleDOI
TL;DR: In this article, the resolution of the identify (RI) was used to replace the use of four-index-two-electron integrals with linear combinations of three-index integrals.

1,112 citations


Journal ArticleDOI
TL;DR: In this article, a set of five-component d-type polarization functions was optimized for the main group elements AlBi at the energetically lowest lying s 2 p n electronic states for use with the effective core potentials of Hay and Wadt at the CISD level of theory.

858 citations


Journal ArticleDOI
TL;DR: In this paper, a new method is described for the calculation of the magnetic susceptibility and nuclear magnetic shielding tensors using a separate gauge origin for each point in space to calculate the magnetically induced current.

845 citations


Journal ArticleDOI
TL;DR: In this paper, a new method for estimating absolute and relative entropies of conformers of a macromolecule was proposed based on the evaluation of the covariance matrix of Cartesian positional coordinates obtainable by computer simulation.

586 citations


Journal ArticleDOI
TL;DR: In this paper, an efficient and reasonably accurate grid, designated SG-1, is proposed for use in density functional calculations, defined for all atoms from H to Ar, and recommended as a standard grid, analogous to the various standard basis sets which are used in contemporary quantum chemistry.

441 citations


Journal ArticleDOI
TL;DR: In this article, an extension of the earlier multi-reference linearized coupled-cluster method to include quadratic EPV terms in an averaged way is presented, which is conceptually similar to the averaged coupled pair functional but offers superior performance particularly with small reference spaces.

413 citations


Journal ArticleDOI
TL;DR: In this article, the ACES II program system has been implemented with the equation-of-motion coupled-cluster method (EOM-CCSD) and its quadratic CI variant for excited states and results for open and closed-shell reference states are reported for Be, N 2, CO, O 2, and O 3.

409 citations


Journal ArticleDOI
TL;DR: In this article, the first and second-order Raman spectra of closed-carbon nanostructures (nanotubes and nanoparticles) have been measured and compared to those of glassy carbon and highly oriented pyrolitic graphite.

401 citations


Journal ArticleDOI
TL;DR: In this paper, the relationship between the phonon modes in carbon nanotubules and those in a graphene sheet is studied by use of the zonefolding method, and the modes identified with pure translations and rotations are identified.

Journal ArticleDOI
Milan Randić1
TL;DR: In this paper, a novel molecular descriptor for the study of structure was proposed, which is derived from a matrix associated with molecular graph, the entries of which are related to the Wiener number.

Journal ArticleDOI
TL;DR: In this paper, graphite tubules and polyhedral particles grown on an electrode surface of arc-discharge have been studied by electron microscopy and the observations of their structures and morphologies lead to a growth model in which ion bombardment and high electric field at the tip of a tubule play crucial roles for the tube growth.

Journal ArticleDOI
TL;DR: In this paper, the stretching vibrations of jet-cooled phenol and phenol (H 2 O) n (n = 1-3) complexes were investigated by IR-UV double-resonance spectroscopy.

Journal ArticleDOI
TL;DR: A new material containing macroscopic quantities of hollow nanometric carbon onions with from 2 to about 8 graphitic shells, with outer diameters ranging from 3 to 10 nm (characterized by high-resolution electron microscopy), is produced by heat treatment of pure carbon soot.

Journal ArticleDOI
TL;DR: In this article, a small-angle scattering deflection method was proposed to determine the size distribution of large liquid helium clusters formed by condensation in a supersonic expansion, and the size distributions can be well represented by a log-normal model with mean sizes varying between 3×103 and 104 atoms depending on the source conditions.

Journal ArticleDOI
TL;DR: In this paper, local density functional calculations on a series of neutrals radicals demonstrate that the unrestricted Kohn-Sham wave function is much less contaminated by higher spin states than its unrestricted Hartree-Fock couterpart, even for radicals which exhibit major contamination in their standard UHF wavefunction.

Journal ArticleDOI
Kimihiko Hirao1
TL;DR: In this article, the same Moller-Plesset perturbation theory was applied to the study of electron correlations in the ground state, singlet and triplet excited states, ionized states and electron attached states of H 2 O. The results compare well with SAC/SAC-CI and full-CI results.

Journal ArticleDOI
Haruyuki Nakano1
TL;DR: A quasidegenerate perturbation theory (QDPT) with Epstein-Nesbet partitioning based on MCSCF reference functions is presented in this paper, where the formulas for CSF-based matrix operations are derived.

Journal ArticleDOI
TL;DR: In this article, a Gaussian basis set leading to wave functions with atomic total energies within 1 m E h of the Hartree-Fock values was prepared using the well-tempered formula for atoms Ga through Rn.

Journal ArticleDOI
TL;DR: In this paper, the pulsed laser-photolysis (PLP), time-resolved laser-induced fluorescence (LIF) technique has been used to study the reactions of the CN radical with CH 4, C 2 H 6, C 2H 4 and C 3 H 6 at low and ultra-low temperatures.

Journal ArticleDOI
TL;DR: In this paper, the structure and stability of four possible isomers of C 24 and B 12 N 12 have been investigated by means of ab initio calculations at the MP2/DZP level.

Journal ArticleDOI
TL;DR: In this paper, the authors performed MP2 calculations on selected structures of (H2O)6 and found that a prism-like structure was the lowest energy structure, but three other structures were found to lie within 0.3 kcal/mol of this structure.

Journal ArticleDOI
TL;DR: In this article, a liquid solution synthesis for preparing single crystal germanium quantum wires is presented, based on the reduction of GeCl 4 and phenyl-GeCl 3 by sodium metal in an alkane solvent at elevated temperature and pressure.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the quenching properties of both excitonic and trapped fluorescence of quantum-sized CdS colloids and found that nitromethane is only able to quench the excITonic fluorescence nearly completely, whereas a fraction of the trapped fluorescent fluorescence always remains.

Journal ArticleDOI
TL;DR: In this paper, the solvent effect on the electronic structure of a solute molecule in the liquid phase was evaluated using the Hartree-Fock and extended reference interaction site model integral equations.

Journal ArticleDOI
TL;DR: In this article, a wet chemical synthetic route is presented for the preparation of a spherical quantum well, which consists of a core of size-quantized CdS, a monolayer of HgS and approximately four monolayers of CcS as the outermost shell.

Journal ArticleDOI
TL;DR: In this article, the metallofullerene LaC 82 has been isolated for the first time from the carbon soot using two-step liquid chromatographic method, and it was well identified as a stable molecule classified to a novel family of fullerene cage molecules.

Journal ArticleDOI
TL;DR: In this paper, the optical properties of red perylimide laser dye in various solvents were studied, including cyclohexane, methanol and xylenes.

Journal ArticleDOI
TL;DR: In this paper, it was shown that the inversion of an integrable Hamiltonian with respect to the action of the reactive coordinate may be avoided in computing the thermal rate constant, and the resulting expression provides an appealing link to conventional transition state theory.