Extension of a simplified method for molecular correlation energy calculations to molecules containing third row atoms. I. Methodological developments

An extension of a simplified method for molecular correlation energy calculations to molecules containing third row atoms is presented. In addition to the use of pseudo-potentials in the calculations, the consequences of this extension on the different components of the energy partition which is the basic idea of the method, is analysed. Particular emphasis is placed on the specific role played by the 3d orbitals in each of the energy components. First, at the zeroth order, the energy is found to be very sensitive to the optimization of the 3d polarization functions. Secondly, the internal correlation energy, calculated by CI, requires the optimization of distinct 3d correlation orbitals to describe adequately the strong near-degeneracy effects that occur within the valence space. Finally it is shown that the 3d orbitals contribute partially to the non-internal correlation energy and that, the atoms-in-molecule structures corresponding typically to all-external contributions are negligible. The concept of error energy is introduced in place of the non-internal correlation energy: it includes the relativistic contributions within the semi-empirical tables. Such tables are presented for second row atoms and for the chlorine atom. From these tables, predicted values for some atomic term energies, experimentally undetermined, are derived. The methodological tests are limited here to the chlorine atom which is chosen for further applications in the next paper of this series. The conclusions concerning the applicability of the method to third row atoms are however quite general.Boursier I.R.S.I.A     

Lattice defects in poly(p-phenylene-terephthalamide) fibers

The lattice defects in PPTA fibers were studied by line profile analysis. The results indicate that lattice distortions are produced by local defects, probably chain ends incorporated into the crystalline lattice. The disorder is strongly anisotropic. There are indications for the existence of small domains of higher disorder which do not disappear on annealing.Dedicated to Professor Dr. R. Bonart on the occasion of his 60th birthday.     

T0-spaces and pointwise convergence

The purpose of this paper is to give several different characterizations of those T₀-spaces E with the property that if F:X × E → Y is separately continuous, then it is jointly continuous. One such is that the lattice 0(E) of open sets of E be a hypercontinuous lattice (i.e. the interval topology on 0(E) is Hausdorff). If E is a sober space, then E must be a quasicontinuous poset endowed with the Scott topology.     

Lattice square approach to construction of mutually orthogonalF-squares

Summary Factorial design theory has been effectively used in solving problems associated with many combinatorial structures. Hedayat, Raghavarao and Seiden [7] clearly demonstrated this in obtaining various results onF(n, λ)-squares. Indeed, both theorems in their paper are cute observations if knowledge of factorial design theory is assumed. The objective of this paper is to present the lattice square method for obtaining sets of mutually orthogonalF(n, λ)-squares of given ordern. As a by-product a generalization of a theorem, due to the above authors, is obtained and a lower bound is presented for the number of mutually orthogonalF(n, λ)-squares on sets of various cardinalities associated with the canonical decomposition ofn as a product of powers of distinct primes.     

IR-active lattice modes of α-glycine and deutero-α-glycine

The 9 IR-active lattice modes of alpha-glycine have been observed in the far-infrared using a Fourier transform Michelson interferometer.     

Nonequilibrium steady states of stochastic lattice gas models of fast ionic conductors

We investigate theoretically and via computer simulation the stationary nonequilibrium states of a stochastic lattice gas under the influence of a uniform external fieldE. The effect of the field is to bias jumps in the field direction and thus produce a current carrying steady state. Simulations on a periodic 30 × 30 square lattice with attractive nearest-neighbor interactions suggest a nonequilibrium phase transition from a disordered phase to an ordered one, similar to the para-to-ferromagnetic transition in equilibriumE=0. At low temperatures and largeE the system segregates into two phases with an interface oriented parallel to the field. The critical temperature is larger than the equilibrium Onsager value atE=0 and increases with the field. For repulsive interactions the usual equilibrium phase transition (ordering on sublattices) is suppressed. We report on conductivity, bulk diffusivity, structure function, etc. in the steady state over a wide range of temperature and electric field. We also present rigorous proofs of the Kubo formula for bulk diffusivity and electrical conductivity and show the positivity of the entropy production for a general class of stochastic lattice gases in a uniform electric field.Supported in part by National Science Foundation Grant DMR81-14726 and NATO Grant 040.82.Work supported in part by a Lafayette College Junior Faculty Leave Grant.Work supported in part by a Heisenberg fellowship of the Deutsche Forschungsgemeinschaft.     

修正的Thomas-Fermi模型及惰性气体原子抗磁磁化率的计算（Ⅰ）

 在本文中，我们在Thomas-Fermi（TF）及Thomas-Fermi-Amadi（TFA）模型下，选用Jensen的试验密度函数，在考虑到TF模型所确定的密度渐近行为情况下，计算了惰性气体原子Ne、Ar、Kr、Xe、Rn的抗磁磁化率。计算表明，考虑密度渐近行为式是必要的，并给出了较以往的同类计算更好的结果。     

Submodular linear programs on forests

A general linear programming model for an order-theoretic analysis of both Edmonds' greedy algorithm for matroids and the NW-corner rule for transportation problems with Monge costs is introduced. This approach includes the model of Queyranne, Spieksma and Tardella (1993) as a special case. We solve the problem by optimal greedy algorithms for rooted forests as underlying structures. Other solvable cases are also discussed.