Showing papers in "Computer Physics Communications in 1997"

TL;DR: The fhi96md as discussed by the authors is an efficient code to perform density-functional theory total energy calculations for materials ranging from insulators to transition metals, and employs first-principles pseudopotentials, and a plane-wave basis set.

TL;DR: In this paper, a Fortran 77 Monte Carlo program is used to simulate complete events in deep inelastic lepton-nucleon scattering, where the parton level interaction is based on the standard model electroweak cross sections, which are fully implemented in leading order for any lepton of arbitrary polarization.

TL;DR: In this article, the Coupled Perturbed Kohn-Sham equations have been implemented in the Amsterdam Density Functional program package, which is approximately 10 times faster than a finite difference algorithm, and the absolute CPU times also compare favorably with other reported implementations.

TL;DR: The preconditioned conjugate-gradient method is developed for this minimization problem and is shown to improve the parallel efficiency by increasing data locality and the computational cost is further amortized due to the algorithmic similarity to the multiple-time-scale MD.

TL;DR: In this paper, an implementation of analytic second derivatives with respect to nuclear displacements, based on density functional theory within the Kohn-Sham formalism, is reported. But the efficiency of the algorithm is tested in comparison with finite difference methods.

TL;DR: In this article, the Schrodinger equation for the Morse potential has an analytically known solution, and the Dirac equation for a muonic atom, as well as a non-localSchrodinger integrodifferential equation that models the n + α system in the framework of the resonating group method.

TL;DR: Several numerical tests are presented demonstrating the applicability of the nested grid code to many astrophysical problems including phenomena in which steep gradients such as shocks or contact discontinuities appear.

TL;DR: In this paper, a new version of the Monte Carlo program for small-angle Bhabha scattering BHLUMI with an overall precision of 0.11% is presented, where the main improvements are in the matrix element of the main multi-photon sub-generator based on the Yennie-Frautschi-Suura exponentiation, where missing second-order terms in the leading-logarithmic approximation are supplemented and the contribution from the Z resonance is improved.

TL;DR: The paper presents the KINX code for computing linear ideal MHD growth rates and eigenvectors of axisymmetric plasmas surrounded by a vacuum layer and a conducting wall and an inverse vector iteration method and a vectorizable matrix solver are applied to the matrix eigenvalue problem.

TL;DR: In this article, a procedure for modifying some standard algorithms with the aim of making them tuned on oscillatory functions is introduced, which is general enough to allow amending many other classical algorithms.

TL;DR: The GRACE system has been used to produce the computational code for all fermionic final states, giving a higher level of confidence in the calculation correctness as discussed by the authors, which is a Monte Carlo package for generating e + e − → 4-fermion processes in the standard model.

TL;DR: The method is systematic and is based upon centre manifold theory, particularly suitable to implementation by computer algebra, for the derivation of low-dimensional models of dynamical systems.

TL;DR: A Fortran program for the calculation of the ground state properties of axially deformed even-even nuclei in the framework of Relativistic Mean Field Theory (RMF) is presented in this article.

TL;DR: In this paper, a Fortran program is described which calculates the reduced density matrix of a one-dimensional quantum mechanical continuous or discrete system coupled to a harmonic dissipative environment, based on Feynman's path integral formulation of time-dependent quantum mechanics.

TL;DR: ASAD as mentioned in this paper is a plug-in subroutine library to solve atmospheric chemistry time-dependent problems, a chemical reaction database and utility programs, which is designed to be coupled to any type of atmospheric model and can be used as far as possible as a black box.

TL;DR: In this paper, a localised spherical-wave basis set suitable for O(N ) total energy pseudopotential calculations is considered. But the basis set is conveniently truncated using a single parameter, the kinetic energy cutoff used with the plane-wave based basis.

TL;DR: C++ and Fortran 90 are compared as object-oriented languages for use in scientific computing, which allows C++ programmers to build portable, reusable code and to dramatically improve the efficiency of the evaluation of complex expressions involving user-defined data types.

TL;DR: In this paper, the authors describe parameterizations of realistic e±- and γ-beam spectra at future linear e+e−-colliders, focusing on simplicity and reproducibility of the parameterizations.

TL;DR: The nonlinear filter which has been investigated there is extended by running several Kalman filters in parallel by developing the correct smoothing algorithm and discussing the treatment of non-Gaussian process noise.

TL;DR: The theoretical and computational framework of the linear-scaling method is summarised, in order to identify the main classes of computer operation required and the issues involved in distributing tasks and data between processors are discussed and a solution is proposed.

TL;DR: In this article, the convergence behavior of the Ewald-like summation methods is analyzed for different magnitudes of the nonperiodic z-separation between the charged particles up to twice the length of the square simulation cell.

TL;DR: In this article, a Fortran program is presented to solve diverse few-body problems with the stochastic variational method, which is applicable for N = 2-3-4-5-6-…-body systems with L = 0 total orbital momentum.

TL;DR: In this paper, the authors present a first order ODE solver and mutines for the explicit determination of the coefficients of the infinitesimal symmetry generator, the construction of the most general invariant first-order ODE under given symmetries, and the determination of canonical coordinates of the underlying invariant group.

TL;DR: In this article, the authors describe a four-step exponential-fitted method for systems of second-order differential equations of the form y″ = ƒ(x,y) which is a sixth-order method depending on five parameters which are automatically adjusted in terms of the equations to be solved.

TL;DR: In this article, the stability and accuracy of the advection phase calculation of the Cubic Interpolated Propagation scheme, which solves the universal hyperbolic equation, were examined using Fourier analysis.

TL;DR: The W W and Higgs Physics with PHACT (WPHACT) MC program as discussed by the authors is a MC program and unweighted event generator which computes all Standard Model processes with four fermions in the final state at e+e− colliders.

TL;DR: In this paper, a C++ class library offers a choice of integration algorithms for three important unravellings of the master equation, which can be used for a wide range of open quantum systems by unravelling the density operator evolution into individual stochastic trajectories in Hilbert space.

TL;DR: In this article, a program to simulate the production of heavy quarks through the boson-gluon fusion process in e±p collisions is presented, where the full electroweak structure of the electron-gluon interaction is taken into account as well as the masses of the produced heavy quark.

TL;DR: In this paper, a numerical scheme applicable to a wide variety of partial differential equations (PDEs) in space and time is presented, which is based on a high accurate interpolation of the profile for the independent variables over a local area and repetitive differential operations regarding PDEs as differential operators.

TL;DR: Methods for applying domain decomposition to a general purpose molecular dynamics program suitable for either distributed memory parallel computers or shared memory machines with message passing libraries are described.