Showing papers in "Chemical Physics in 1986"

TL;DR: In this paper, it was shown that spin polarized determinants for an antiferromagnetic transition metal dimer and spin projected states obtained from them contribute to the Heisenberg coupling constant J describing a ladder of spin states.

TL;DR: In this paper, the authors compare channel shift, pseudoscatterer, excitation pulse-shape mimic and delta function convolution (DFC) methods for single photon counting.

TL;DR: The ground and excited-state electronic structure of the highly polar squaraine dye bis(4-dimethylaminophenyl)squaraine, or 2,4-bis (4-methylcyclobutadienediylium-1,3-diolate, is addressed using the MNDO and CNDO/S(S + DES CI) semi-empirical molecular orbital approximations in this article.

TL;DR: In this paper, a detailed analysis of the vibrational motions of water in a 1.1 M aqueous CaCl2 solution is presented on the basis of molecular dynamics computer simulations.

TL;DR: In this paper, the vibrational levels of the ground state of the X 1 Σ + g ground state were analyzed by laser-induced fluorescence Fourier transform spectrometry.

TL;DR: In this paper, a new method for calculating the energies and widths of quasi-bound levels is presented, which introduces a trial optical potential in the outer potential region, which suppresses reflections from the artificial "wall" present in a finite basis calculation.

TL;DR: In this article, photo absorption cross sections and the fluorescence quantum yields of H2O and D2O were measured in the 50-190 nm region using synchrotron radiation as a light source.

TL;DR: The possibilites for applying the ab initio matrix block negative factor counting technique (NFC) for non-periodic nucleotide base stacks and for 4-and 5-component aperiodic model proteins are described in this article.

TL;DR: In this article, the orientational distribution function of cylindrically symmetric probe molecules in uniaxial systems is constructed from orientational order parameters using information theory, and a reanalysis of time-resolved fluorescence anisotropy data indicates that the so-called P4 >-distribution is a good model for diphenylhexatriene in non-oriented membranes.

TL;DR: In this article, the magnitudes and temperature dependence of the single crystal g-values of ≈≈ 1% Cu2+ doped into tetragonal K2ZnF4 measured over a temperature range between 4 and 295 K are reported.

TL;DR: In this article, photo-induced electron transfer from porphyrins to quinone and methylviologen capping groups has been demonstrated to occur on the picosecond time scale.

TL;DR: In this paper, the non-markovian encounter theory is extended to kinetic calculations of an exciton (electron) contact transfer between an energy (charge) donor and acceptor, which is shown to be non-stationary from the beginning to the end if the donor state relaxation time is shorter than the encounter time.

TL;DR: In this paper, a chargeconsistent version of the relativistic extended Huckel method REX is presented and the diagonal matrix elements are corrected for occupations of individual orbitals on the same atom using derivatives from atomic Dirac-Slater calculations and for external charges.

TL;DR: In this paper, a sliding mass model for three-center reactions is formulated, which proves to be useful to rationalize the dependence of integral reaction cross section on reagent rotation by topographic attributes of the potential energy surface (PES).

TL;DR: In this paper, the structures of the dimers (H 2 O) 2, HOHSH 2, HSHSH 2,HSHOH 2 and H 2 S 2 were obtained at the SCF level.

TL;DR: In this paper, three stable dimer configurations of bacteriochlorophyll a are predicted by a selfconsistent field molecular orbital calculation (all valence electrons, restricted Hartree-Fock, INDO-parametrization, perturbational treatment of spin polarization) including geometry optimization by energy minimization.

TL;DR: In this article, the authors reported the results of calculation of the intramolecular vibrational relaxation (IVR) rate of an isolated polyatomic molecule in a broad range of energies.

TL;DR: In this article, a method of calculating the pair correlation function from liquid structure factor measurements is described, which attempts to maximize the entropy of the calculated distribution, and the solution is forced to lie as close as possible to the measured data by means of a feedback procedure.

TL;DR: In this article, a discussion is given on the many-electron effect in interperting Cu K-edge XANES spectra of several Cu(II) and Cu(I) compounds.

TL;DR: In this paper, the authors define valence virtual MOs to perform full CAS CI or to use them in other approximate CI expansions, and compare the quality of their MO sets at the valence CAS CI level and through the convergence of the iterative multireference second-order Moller-Plesset CIPSI algorithm.

TL;DR: In this paper, a comprehensive investigation of the two-color threshold photoionization of jet-cooled indole clusters was performed using two-colour photoionisation spectroscopy, which allowed the determination of accurate cluster ionization energies (IEs) as well as assignment of electronic absorption features to clusters of known composition.

TL;DR: In this article, a double-zeta basis set including polarization and Rydberg-type orbitals is used to study the first three ionization potentials and the vertical electronic spectrum of H 2 O 2 in the spectral region below 10.5 eV.

TL;DR: The adiabatic vibronic couplings due to the a g CC stretching modes between the lowest electronic states of a few polyenes have been obtained by quantum mechanical calculations as discussed by the authors.

TL;DR: In this article, an ab initio all-electron self-consistent field plus configuration interaction (CI) study of simple models of dichloro- and difluoro-bridged Cu(II) dimers was conducted.

TL;DR: In this paper, the concept of Bloch effective hamiltonian can be used to extract the electronic coupling parameter between S 1 and S 2 sites, and the application is performed on the model compound Ru-bipyridylbutadiene-Ru(NH 3 ) 5 in order to investigate theoretically the possibility of molecular switching.

TL;DR: In this paper, the first and second-row hydrides in the GIAO SCF using heavy atom triplet-split-valence bases were calculated for NMR chemical shifts and shift derivatives upon bond extension.

TL;DR: In this article, the minimal basis set Hartree-Fock and full-CI wavefunctions of some molecules (N2, CO, BH2, CH4) are analyzed in terms of their valence-bond components.

TL;DR: In this article, the adiabatic and the vertical ionization energy of the ammonia dimer as well as the appearance energies of NH+4 and (NH3)+2 have been obtained from ab initio potential energy surface calculations.

TL;DR: In this article, a method for the separate determination of net and multiplet type CIDNP effects in chemical reactions is developed based on the principles of Fourier spectroscopy of non-equilibrium systems.

TL;DR: In this paper, state-to-state cross sections have been calculated for collisions of N + 2 (X, υ) or N+ 2 (A, ε) with Ar at relative energies of 8 and 20 eV.