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Showing papers in "Chemical Physics Letters in 1989"


Journal ArticleDOI
TL;DR: TURBOMOLE as discussed by the authors is a program system for SCF that takes full advantage of all discrete point group symmetries and has only modest I/O and background storage requirements.

7,616 citations


Journal ArticleDOI
TL;DR: In this paper, a new augmented version of coupled-cluster theory, denoted as CCSD(T), is proposed to remedy some of the deficiencies of previous augmented coupledcluster models.

7,249 citations


Journal ArticleDOI
TL;DR: In this paper, the correlation contributions to ionization energies, electron affinities and dissociation energies of first-row atoms, ions and molecules were calculated using density functionals.

6,307 citations


Journal ArticleDOI
TL;DR: In this article, a computationally efficient molecular dynamics method for estimating the rates of rare events that occur by activated processes is described, where the system is constrained at bottleneck regions on a general many-body reaction coordinate in order to generate a biased configurational distribution.

835 citations


Journal ArticleDOI
TL;DR: In this article, the matrix elements of one-and two-electron operators for CASSCF wavefunctions employing individually optimized orbitals are computed using the Hamiltonian secular problem.

756 citations


Journal ArticleDOI
TL;DR: In this article, a method for obtaining electron-repulsion integrals over a molecular-orbital basis without any explicit four-index transformation involving input/output is proposed, which allows for calculations that would otherwise be prohibited by storage limitations with conventional techniques.

697 citations


Journal ArticleDOI
TL;DR: In this paper, an equation of motion coupled-cluster (EOM-CC) method for the calculation of excitation energies is presented, which is based upon representing an excited state as an excitation from a ground state and the excitation energy is obtained by solving a non-Hermitian eigenvalue problem.

588 citations


Journal ArticleDOI
TL;DR: In this article, a size-consistent set of equations for electron correlation which are limited to double substitutions, based on Brueckner orbitals, is discussed, and it is shown that at fifth order of perturbation theory, BD incorporates more terms than CCSD and QCISD.

476 citations


Journal ArticleDOI
TL;DR: In this article, a new rf pulse sequence is described for the decoupling of homonuclear dipolar interactions in solid state NMR, which involves alternate 2π rotations of opposite signs about the magic-angle axis in spin space, by π rf phase shifts synchronous with rapid switching of the rf carrier frequency between opposite sides of resonance.

460 citations


Journal ArticleDOI
TL;DR: In this article, two silica sheets were immersed in aqueous solutions of NaCl to study both the surface forces between them and the viscosity of the intervening NaCl film.

371 citations



Journal ArticleDOI
TL;DR: In this article, a method for enforcing nuclear Overhauser effect (NOE) distance restraints in molecular dynamics simulations is presented, in which a term is included in the force field such that the distance restraint need only be satisfied as a ǫ r −3 −1/3 weighted time average over the simulation trajectory.

Journal ArticleDOI
TL;DR: In this article, the primary light-induced charge separation in reaction centers of Rhodobacter sphaeroides was investigated with femtosecond time resolution, showing that the absorption changes in the time range 100 fs to 1 ns observed after direct excitation of the primary donor P at 860 nm could only be explained by a kinetic model which uses three time constants.

Journal ArticleDOI
TL;DR: In this paper, negative ion photoelectron spectroscopy was used to examine the O 2 − and NO − spectra of O 2 and showed the following electron affinities: EA (O 2 )=0.451±0.007 eV and EA(NO)=0.026± 0.005 eV.

Journal ArticleDOI
TL;DR: In this paper, a coupled-cluster method (UCC( n )) for correlation energies and properties is developed based upon a unitary cluster ansatz and a finite-order truncation of the energy functional.

Journal ArticleDOI
TL;DR: In this article, a 6 fs optical pulse was used to impulsively excited the entire manifold of Franck-Condon-connected vibronic levels for the S 0 to S 1 transition in an organic dye in solution.

Journal ArticleDOI
TL;DR: In this article, a dynamical theory for the rate constant k of hydrogen atom and proton transfer reactions in solution is presented for the nonadiabatic limit, where reaction is dominated by tunneling.

Journal ArticleDOI
TL;DR: In this paper, the rise and decay kinetics of singlet oxygen luminescence induced by flash laser excitation were measured with 10 ns resolution in aqueous solutions of tetra (p-sulfophenyl)porphyrin at various oxygen pressures.

Journal ArticleDOI
TL;DR: In this paper, the femtosecond transition-state spectroscopy (FTS) was applied to molecular iodine and the real-time motion of wave packets prepared coherently in the bound B state was observed.

Journal ArticleDOI
TL;DR: In this paper, the authors have simulated the solvent relaxation immediately after photoinduced electron transfer of an aqueous ferric-ferrous system and showed that the process occurs in a sub-picosecond time scale.

Journal ArticleDOI
TL;DR: In this article, a close coupling calculation of integral cross sections for the reaction H + H 2 (v = 0, j = 0) → H 2(v, odd j ′) + H has been performed in the energy range E tot = 0.9 − 1.4 eV using hyperspherical coordinates.

Journal ArticleDOI
TL;DR: In this article, an eigenvalue-independent partitioning technique in Fock space is proposed to convert the CC equations for each m -hole, n -particle model space of dimension N (m,n) to a non-Hermitian eigenproblem of larger dimension.

Journal ArticleDOI
TL;DR: In this article, the reaction field method was used to calculate the constant temperature molecular dynamics (N, V, T ensemble) on 216 SPC/E water molecules at temperatures T =298 and 373 K and density 1 g/cm 3.

Journal ArticleDOI
TL;DR: In this article, a stepwise relaxation model was proposed for a TICT state (twisted single-bond conformation) as the main fluorescent species and temperature-activated non-radiative decay via a photochemical funnel with twisted double-bund conformation.

Journal ArticleDOI
TL;DR: In this article, a delayed pulsed field ionization technique was used in combination with a high-resolution VUV radiation source to measure the rotational structure associated with the X 2 Π g ←X 3 Σ g − (0, 0) ionizing transition in O 2.

Journal ArticleDOI
TL;DR: In this paper, the third-harmonic generation measurements have been performed at λ 0 = 1064 nm on ultrathin films of polyphenylacetylene and the nonlinear susceptibility χxxx x(3) was determined to be (7.0±1.0)×10−13 esu with the phase of χ(3), equal to 152°±5° indicating that two and three-photon resonances contribute to the observed nonlinearity.

Journal ArticleDOI
TL;DR: In this article, photo-evaporation spectra of mass-selected potassium cluster ions K 9 + and K 21 + were obtained in the range 0.6 to 4.7 eV.

Journal ArticleDOI
TL;DR: In this paper, the authors used photofragment imaging to study the internal state and velocity distributions of methyl fragments following photodissociation of CH 3 I molecules in a pulsed molecular beam by 266 nm radiation.

Journal ArticleDOI
TL;DR: In this paper, the authors reported the preparation and crystal structure of 3-methyl-4-methoxy-4′-nitrostilbene (MMONS), which is the largest measured powder SHG efficiency reported to date.

Journal ArticleDOI
TL;DR: In this article, a scanning tunneling microscope was modified so that the currentvoltage characteristics between the tip and a surface could be obtained rapidly, making it possible to observe the effects of single molecules.