Introducing PROFESS: A new program for orbital-free density functional theory calculations

We present PROFESS (PRinceton Orbital-Free Electronic Structure Software), a new software package that performs orbital-free density functional theory (OF-DFT) calculations. OF-DFT is a first principles quantum mechanics method primarily for condensed matter that can be made to scale linearly with system size. We describe the implementation of energy, force, and stress functionals and the methods used to optimize the electron density under periodic boundary conditions. All electronic energy and potential terms scale linearly while terms involving the ions exhibit quadratic scaling in our code. Despite the latter scaling, the program can treat tens of thousands of atoms with quantum mechanics on a single processor, as we demonstrate here. Limitations of the method are also outlined, the most serious of which is the accuracy of state-of-the-art kinetic energy functionals, which limits the applicability of the method to main group elements at present.

Program summary

Program title: PROFESSCatalogue identifier: AEBN_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEBN_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 35 933No. of bytes in distributed program, including test data, etc.: 329 924Distribution format: tar.gzProgramming language: Fortran 90Computer: Intel with ifort; AMD Opteron with pathf90Operating system: LinuxRAM: Problem dependent, but 2 GB is sufficient for up to 10,000 ionsClassification: 7.3External routines: FFTW (http://www.fftw.org), MINPACK-2Nature of problem: Given a set of coordinates describing the initial ion positions under periodic boundary conditions, recovers the ground state energy, electron density, ion positions, and cell lattice vectors predicted by orbital-free density functional theory. Except for computation of the ion-ion and ion-electron terms, all other terms are effectively linear scaling. Up to ∼10,000 ions may be included in the calculation on just a single processor.Solution method: Computes energies as described in text; minimizes this energy with respect to the electron density, ion positions, and cell lattice vectors.Restrictions: PROFESS cannot use nonlocal (such as ultrasoft) pseudopotentials. Local pseudopotential files for aluminum, magnesium, silver, and silicon are available upon request. Also, due to the current state of the kinetic energy functionals, PROFESS is only reliable for main group metals and some properties of semiconductors.Running time: Problem dependent: the test example provided with the code takes less than a second to run. Timing results for large scale problems are given in the paper.References:[1] Y.A. Wang, N. Govind, E.A. Carter, Phys. Rev. B 58 (1998) 13465;  Y.A. Wang, N. Govind, E.A. Carter, Phys. Rev. B 64 (2001) 129901 (erratum).[2] S.C. Watson, E.A. Carter, Comput. Phys. Comm. 128 (2000) 67.     

A web-deployed interface for performing ab initio molecular dynamics, optimization, and electronic structure in Fireball

Fireball is an ab initio technique for fast local orbital simulations of nanotechnological, solid state, and biological systems. We have implemented a convenient interface for new users and software architects in the platform-independent Java language to access Fireball's unique and powerful capabilities. The graphical user interface can be run directly from a web server or from within a larger framework such as the Computational Science and Engineering Online (CSE-Online) environment or the Distributed Analysis of Neutron Scattering Experiments (DANSE) framework. We demonstrate its use for high-throughput electronic structure calculations and a multi-100 atom quantum molecular dynamics (MD) simulation.

Program summary

Program title: FireballUICatalogue identifier: AECF_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECF_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 279 784No. of bytes in distributed program, including test data, etc.: 12 836 145Distribution format: tar.gzProgramming language: JavaComputer: PC and workstationOperating system: The GUI will run under Windows, Mac and Linux. Executables for Mac and Linux are included in the package.RAM: 512 MBWord size: 32 or 64 bitsClassification: 4.14Nature of problem: The set up and running of many simulations (all of the same type), from the command line, is a slow process. But most research quality codes, including the ab initio tight-binding code FIREBALL, are designed to run from the command line. The desire is to have a method for quickly and efficiently setting up and running a host of simulations.Solution method: We have created a graphical user interface for use with the FIREBALL code. Once the user has created the files containing the atomic coordinates for each system that they are going to run a simulation on, the user can set up and start the computations of up to hundreds of simulations.Running time: 3 to 5 minutes on a 2 GHz Pentium IV processor.     

Plato: A localised orbital based density functional theory code

The Plato package allows both orthogonal and non-orthogonal tight-binding as well as density functional theory (DFT) calculations to be performed within a single framework. The package also provides extensive tools for analysing the results of simulations as well as a number of tools for creating input files. The code is based upon the ideas first discussed in Sankey and Niklewski (1989) [1] with extensions to allow high-quality DFT calculations to be performed. DFT calculations can utilise either the local density approximation or the generalised gradient approximation. Basis sets from minimal basis through to ones containing multiple radial functions per angular momenta and polarisation functions can be used. Illustrations of how the package has been employed are given along with instructions for its utilisation.

Program summary

Program title: PlatoCatalogue identifier: AEFC_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFC_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 219 974No. of bytes in distributed program, including test data, etc.: 1 821 493Distribution format: tar.gzProgramming language: C/MPI and PERLComputer: Apple Macintosh, PC, Unix machinesOperating system: Unix, Linux and Mac OS XHas the code been vectorised or parallelised?: Yes, up to 256 processors testedRAM: Up to 2 Gbytes per processorClassification: 7.3External routines: LAPACK, BLAS and optionally ScaLAPACK, BLACS, PBLAS, FFTWNature of problem: Density functional theory study of electronic structure and total energies of molecules, crystals and surfaces.Solution method: Localised orbital based density functional theory.Restrictions: Tight-binding and density functional theory only, no exact exchange.Unusual features: Both atom centred and uniform meshes available. Can deal with arbitrary angular momenta for orbitals, whilst still retaining Slater–Koster tables for accuracy.Running time: Test cases will run in a few minutes, large calculations may run for several days.     

Generating relativistic pseudo-potentials with explicit incorporation of semi-core states using APE, the Atomic Pseudo-potentials Engine

We present a computer package designed to generate and test norm-conserving pseudo-potentials within Density Functional Theory. The generated pseudo-potentials can be either non-relativistic, scalar relativistic or fully relativistic and can explicitly include semi-core states. A wide range of exchange-correlation functionals is included.

Program summary

Program title: Atomic Pseudo-potentials Engine (APE)Catalogue identifier: AEAC_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAC_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 88 287No. of bytes in distributed program, including test data, etc.: 649 959Distribution format: tar.gzProgramming language: Fortran 90, CComputer: any computer architecture, running any flavor of UNIXOperating system: GNU/LinuxRAM: <5 MbClassification: 7.3External routines: GSL (http://www.gnu.org/software/gsl/)Nature of problem: Determination of atomic eigenvalues and wave-functions using relativistic and nonrelativistic Density-Functional Theory. Construction of pseudo-potentials for use in ab-initio simulations.Solution method: Grid-based integration of the Kohn-Sham equations.Restrictions: Relativistic spin-polarized calculations are not possible. The set of exchange-correlation functionals implemented in the code does not include orbital-dependent functionals.Unusual features: The program creates pseudo-potential files suitable for the most widely used ab-initio packages and, besides the standard non-relativistic Hamann and Troullier-Martins potentials, it can generate pseudo-potentials using the relativistic and semi-core extensions to the Troullier-Martins scheme. APE also has a very sophisticated and user-friendly input system.Running time: The example given in this paper (Si) takes 10 s to run on a Pentium IV machine clocked at 2 GHz.     

HRMC: Hybrid Reverse Monte Carlo method with silicon and carbon potentials

Fortran 77 code is presented for a hybrid method of the Metropolis Monte Carlo (MMC) and Reverse Monte Carlo (RMC) for the simulation of amorphous silicon and carbon structures. In additional to the usual constraints of the pair correlation functions and average coordination, the code also incorporates an optional energy constraint. This energy constraint is in the form of either the Environment Dependent Interatomic Potential (applicable to silicon and carbon) and the original and modified Stillinger-Weber potentials (applicable to silicon). The code also allows porous systems to be modeled via a constraint on porosity and internal surface area using a novel restriction on the available simulation volume.

Program summary

Program title: HRMC version 1.0Catalogue identifier: AEAO_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAO_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 200 894No. of bytes in distributed program, including test data, etc.: 907 557Distribution format: tar.gzProgramming language: FORTRAN 77Computer: Any computer capable of running executables produced by the g77 Fortran compilerOperating system: Unix, WindowsRAM: Depends on the type of empirical potential use, number of atoms and which constraints are employedClassification: 7.7Nature of problem: Atomic modeling using empirical potentials and experimental dataSolution method: Monte CarloAdditional comments: The code is not standard FORTRAN 77 but includes some additional features and therefore generates errors when compiled using the Nag95 compiler. It does compile successfully with the GNU g77 compiler (http://www.gnu.org/software/fortran/fortran.html).Running time: Depends on the type of empirical potential use, number of atoms and which constraints are employed. The test included in the distribution took 37 minutes on a DEC Alpha PC.     

Resolution of singularities for multi-loop integrals

We report on a program for the numerical evaluation of divergent multi-loop integrals. The program is based on iterated sector decomposition. We improve the original algorithm of Binoth and Heinrich such that the program is guaranteed to terminate. The program can be used to compute numerically the Laurent expansion of divergent multi-loop integrals regulated by dimensional regularisation. The symbolic and the numerical steps of the algorithm are combined into one program.

Program summary

Program title: sector_decompositionCatalogue identifier: AEAG_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAG_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 47 506No. of bytes in distributed program, including test data, etc.: 328 485Distribution format: tar.gzProgramming language: C++Computer: allOperating system: UnixRAM: Depending on the complexity of the problemClassification: 4.4External routines: GiNaC, available from http://www.ginac.de, GNU scientific library, available from http://www.gnu.org/software/gslNature of problem: Computation of divergent multi-loop integrals.Solution method: Sector decomposition.Restrictions: Only limited by the available memory and CPU time.Running time: Depending on the complexity of the problem.     

Motion4D - A library for lightrays and timelike worldlines in the theory of relativity

The Motion4D-library solves the geodesic equation as well as the parallel- and Fermi-Walker-transport in four-dimensional Lorentzian spacetimes numerically. Initial conditions are given with respect to natural local tetrads which are adapted to the symmetries or the coordinates of the spacetime. Beside some already implemented metrics like the Schwarzschild and Kerr metric, the object oriented structure of the library permits to implement other metrics or integrators in a straight forward manner.

Program summary

Program title: Motion4D-libraryCatalogue identifier: AEEX_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEX_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 150 425No. of bytes in distributed program, including test data, etc.: 5 139 407Distribution format: tar.gzProgramming language: C++Computer: All platforms with a C++ compilerOperating system: Linux, Unix, WindowsRAM: 39 MBytesClassification: 1.5External routines: Gnu Scientific Library (GSL) (http://www.gnu.org/software/gsl/)Nature of problem: Solve geodesic equation, parallel and Fermi-Walker transport in four-dimensional Lorentzian spacetimes.Solution method: Integration of ordinary differential equationsRunning time: The test runs provided with the distribution require only a few seconds to run.     

TiReX: Replica-exchange molecular dynamics using Tinker

We present a driver program for performing replica-exchange molecular dynamics simulations with the Tinker package. Parallelization is based on the Message Passing Interface, with every replica assigned to a separate process. The algorithm is not communication intensive, which makes the program suitable for running even on loosely coupled cluster systems. Particular attention is paid to the practical aspects of analyzing the program output.

Program summary

Program title: TiReXCatalogue identifier: AEEK_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEK_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 43 385No. of bytes in distributed program, including test data, etc.: 502 262Distribution format: tar.gzProgramming language: Fortran 90/95Computer: Most UNIX machinesOperating system: LinuxHas the code been vectorized or parallelized?: parallelized with MPIClassification: 16.13External routines: TINKER version 4.2 or 5.0, built as a libraryNature of problem: Replica-exchange molecular dynamics.Solution method: Each replica is assigned to a separate process; temperatures are swapped between replicas at regular time intervals.Running time: The sample run may take up to a few minutes.     

wannier90: A tool for obtaining maximally-localised Wannier functions

We present wannier90, a program for calculating maximally-localised Wannier functions (MLWF) from a set of Bloch energy bands that may or may not be attached to or mixed with other bands. The formalism works by minimising the total spread of the MLWF in real space. This is done in the space of unitary matrices that describe rotations of the Bloch bands at each k-point. As a result, wannier90 is independent of the basis set used in the underlying calculation to obtain the Bloch states. Therefore, it may be interfaced straightforwardly to any electronic structure code. The locality of MLWF can be exploited to compute band-structure, density of states and Fermi surfaces at modest computational cost. Furthermore, wannier90 is able to output MLWF for visualisation and other post-processing purposes. Wannier functions are already used in a wide variety of applications. These include analysis of chemical bonding in real space; calculation of dielectric properties via the modern theory of polarisation; and as an accurate and minimal basis set in the construction of model Hamiltonians for large-scale systems, in linear-scaling quantum Monte Carlo calculations, and for efficient computation of material properties, such as the anomalous Hall coefficient. wannier90 is freely available under the GNU General Public License from http://www.wannier.org/.

Program summary

Program title: wannier90Catalogue identifier: AEAK_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAK_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 556 495No. of bytes in distributed program, including test data, etc.: 5 709 419Distribution format: tar.gzProgramming language: Fortran 90, perlComputer: any architecture with a Fortran 90 compilerOperating system: Linux, Windows, Solaris, AIX, Tru64 Unix, OSXRAM: 10 MBWord size: 32 or 64Classification: 7.3External routines:

•

BLAS (http://www/netlib.org/blas).

•

LAPACK (http://www.netlib.org/lapack).

Both available under open-source licenses.Nature of problem: Obtaining maximally-localised Wannier functions from a set of Bloch energy bands that may or may not be entangled.Solution method: In the case of entangled bands, the optimally-connected subspace of interest is determined by minimising a functional which measures the subspace dispersion across the Brillouin zone. The maximally-localised Wannier functions within this subspace are obtained by subsequent minimisation of a functional that represents the total spread of the Wannier functions in real space. For the case of isolated energy bands only the second step of the procedure is required.Unusual features: Simple and user-friendly input system. Wannier functions and interpolated band structure output in a variety of file formats for visualisation.Running time: Test cases take 1 minute.References:

[1] 

N. Marzari, D. Vanderbilt, Maximally localized generalized Wannier functions for composite energy bands, Phys. Rev. B 56 (1997) 12847.

[2] 

I. Souza, N. Marzari, D. Vanderbilt, Maximally localized Wannier functions for entangled energy bands, Phys. Rev. B 65 (2001) 035109.

     

LIBERI: Library for numerical evaluation of electron-repulsion integrals

We provide a C library, called LIBERI, for numerical evaluation of four-center electron repulsion integrals, based on successive reduction of integral dimension by using Fourier transforms. LIBERI enables us to compute the integrals for numerically defined basis functions within ¹⁰−5 Hartree accuracy as well as their derivatives with respect to the atomic nuclear positions. Damping of the Coulomb interaction can also be imposed to take account of screening effect.

Program summary

Program title: LIBERICatalogue identifier: AEGG_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEGG_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 44 091No. of bytes in distributed program, including test data, etc.: 1 692 085Distribution format: tar.gzProgramming language: CComputer: allOperating system: any Unix-like systemRAM: 5-10 MbClassification: 7.4External routines: Lapack (http://www.netlib.org/lapack/), Blas (http://www.netlib.org/blas/), FFTW3 (http://www.fftw.org/)Nature of problem: Numerical evaluation of four-center electron-repulsion integrals.Solution method: Four-center electron-repulsion integrals are computed for given basis function set, based on successive reduction of integral dimension using Fourier transform.Running time: 0.5 sec for the demo program supplied with the package.     

A completely open source based computing system for computer generation of Fourier holograms

Computer generated holograms are usually generated using commercial software like MATLAB, MATHCAD, Mathematica, etc. This work is an approach in doing the same using freely distributed open source packages and Operating System. A Fourier hologram is generated using this method and tested for simulated and optical reconstruction. The reconstructed images are in good agreement with the objects chosen. The significance of using such a system is also discussed.

Program summary

Program title: FHOLOCatalogue identifier: AEDS_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDS_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 176 336No. of bytes in distributed program, including test data, etc.: 4 294 872Distribution format: tar.gzProgramming language: C++Computer: any X86 micro computerOperating system: Linux (Debian Etch)RAM: 512 MBClassification: 18Nature of problem: To generate a Fourier Hologram in micro computer only by using open source operating system and packages.Running time: Depends on the matrix size. 10 sec for a matrix of size 256×256.     

MDVRY: a polarizable classical molecular dynamics package for biomolecules

The MDVRY classical molecular dynamics package is presented for the study of biomolecules in the gas and liquid phase. Electrostatic polarization has been implemented in the formalism of point induced dipoles following the model of Thole. Two schemes have been implemented for the calculation of induced dipoles, i.e. resolution of the self-consistent equations and a ‘Car-Parrinello’ dynamical approach. In this latter, the induced dipoles are calculated at each time step of the dynamics through the dynamics of additional degrees of freedom associated with the dipoles. This method saves computer time and allows to study polarized solvated proteins at a very low CPU cost. The program is written in C-language and runs on LINUX machines. A detailed manual of the code is given. The main features of the package are illustrated taking on examples of proteins in the gas phase or immersed in liquid water.

Program summary

Program title: MDVRYCatalogue identifier: AEBY_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEBY_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 39 156No. of bytes in distributed program, including test data, etc.: 277 197Distribution format: tar.bz2Programming language: CComputer: Linux machines with FFTW Fourier Transform package installedOperating system: Linux machines, SUSE & RedHat distributionsClassification: 3, 16.13, 23External routines: FFTW (http://www.fftw.org/)Nature of problem: Molecular Dynamics Software package.Solution method: Velocity Verlet algorithm. The implemented force field is composed of intra-molecular interactions and inter-molecular interactions (electrostatics, polarization, van der Waals). Polarization is accounted through induced point dipoles at each atomic site. Supplementary degrees of freedom are associated to the induced dipoles so that a modified Hamiltonian of the dynamics is written. This allows to calculate the induced dipoles with a very fast ‘Car-Parrinello’ type of dynamics.Running time: The test run provided takes approximately 6 minutes to run.     

Monte Carlo event generator for black hole production and decay in proton-proton collisions - QBH version 1.02

We describe the Monte Carlo event generator for black hole production and decay in proton-proton collisions - QBH version 1.02. The generator implements a model for quantum black hole production and decay based on the conservation of local gauge symmetries and democratic decays. The code in written entirely in C++ and interfaces to the PYTHIA 8 Monte Carlo code for fragmentation and decays.

Program summary

Program title: QBHCatalogue identifier: AEGU_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEGU_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 10 048No. of bytes in distributed program, including test data, etc.: 118 420Distribution format: tar.gzProgramming language: C++Computer: x86Operating system: Scientific Linux, Mac OS XRAM: 1 GBClassification: 11.6External routines: PYTHIA 8130 (http://home.thep.lu.se/~torbjorn/pythiaaux/present.html) and LHAPDF (http://projects.hepforge.org/lhapdf/)Nature of problem: Simulate black hole production and decay in proton-proton collision.Solution method: Monte Carlo simulation using importance sampling.Running time: Eight events per second.     

Visual tool for estimating the fractal dimension of images

This work presents a new Visual Basic 6.0 application for estimating the fractal dimension of images, based on an optimized version of the box-counting algorithm. Following the attempt to separate the real information from “noise”, we considered also the family of all band-pass filters with the same band-width (specified as parameter). The fractal dimension can be thus represented as a function of the pixel color code. The program was used for the study of paintings cracks, as an additional tool which can help the critic to decide if an artistic work is original or not.

Program summary

Program title: Fractal Analysis v01Catalogue identifier: AEEG_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEG_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 29 690No. of bytes in distributed program, including test data, etc.: 4 967 319Distribution format: tar.gzProgramming language: MS Visual Basic 6.0Computer: PCOperating system: MS Windows 98 or laterRAM: 30MClassification: 14Nature of problem: Estimating the fractal dimension of images.Solution method: Optimized implementation of the box-counting algorithm. Use of a band-pass filter for separating the real information from “noise”. User friendly graphical interface.Restrictions: Although various file-types can be used, the application was mainly conceived for the 8-bit grayscale, windows bitmap file format.Running time: In a first approximation, the algorithm is linear.     

FeynEdit—a tool for drawing Feynman diagrams

We describe the FeynEdit tool for drawing Feynman diagrams. Input and output is done using the macros of FeynArts, which also implies that diagrams drawn by FeynArts can be edited with FeynEdit. The code can be conveniently transferred using copy-and-paste.

Program summary

Program title: FeynEditCatalogue identifier: AEBX_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEBX_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 31 729No. of bytes in distributed program, including test data, etc.: 500 240Distribution format: tar.gzProgramming language: JavaComputer: All Java-capable platformsOperating system: Linux, Mac OS, WindowsRAM: 1-2 MBytesClassification: 4.4Nature of problem: Graphical editing of Feynman diagrams.Solution method: The user copy-and-pastes the LaTeX code of the Feynman diagram into the editor, clicks a button to visualize the diagram, modifies it using the mouse, and finally copy-and-pastes it back into the text.Restrictions: Propagators are presently drawn only as straight lines. This is largely for performance reasons and may be added in a future version. It is not a serious deficit because that information can easily be added in the LaTeX code.Unusual features: Uses FeynArts' LaTeX representation for input and outputRunning time: User-dependent     

Program package for multicanonical simulations of U(1) lattice gauge theory

We document our Fortran 77 code for multicanonical simulations of 4D U(1) lattice gauge theory in the neighborhood of its phase transition. This includes programs and routines for canonical simulations using biased Metropolis heatbath updating and overrelaxation, determination of multicanonical weights via a Wang-Landau recursion, and multicanonical simulations with fixed weights supplemented by overrelaxation sweeps. Measurements are performed for the action, Polyakov loops and some of their structure factors. Many features of the code transcend the particular application and are expected to be useful for other lattice gauge theory models as well as for systems in statistical physics.

Program summary

Program title: STMC_U1MUCACatalogue identifier: AEET_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEET_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 18 376No. of bytes in distributed program, including test data, etc.: 205 183Distribution format: tar.gzProgramming language: Fortran 77Computer: Any capable of compiling and executing Fortran codeOperating system: Any capable of compiling and executing Fortran codeClassification: 11.5Nature of problem: Efficient Markov chain Monte Carlo simulation of U(1) lattice gauge theory close to its phase transition. Measurements and analysis of the action per plaquette, the specific heat, Polyakov loops and their structure factors.Solution method: Multicanonical simulations with an initial Wang-Landau recursion to determine suitable weight factors. Reweighting to physical values using logarithmic coding and calculating jackknife error bars.Running time: The prepared tests runs took up to 74 minutes to execute on a 2 GHz PC.     

Solution of few-body problems with the stochastic variational method II: Two-dimensional systems

A computational approach is presented for efficient solution of two-dimensional few-body problems, such as quantum dots or excitonic complexes, using the stochastic variational method. The computer program can be used to calculate the energies and wave functions of various two-dimensional systems.

Program summary

Program title: svm-2dCatalogue identifier: AEBE_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEBE_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 5091No. of bytes in distributed program, including test data, etc.: 130 963Distribution format: tar.gzProgramming language: Fortran 90Computer: The program should work on any system with a Fortran 90 compilerOperating system: The program should work on any system with a Fortran 90 compilerClassification: 7.3Nature of problem: Variational calculation of energies and wave functions using Correlated Gaussian basis.Solution method: Two-dimensional few-electron problems are solved by the variational method. The ground state wave function is expanded into Correlated Gaussian basis functions and the parameters of the basis states are optimized by a stochastic selection procedure. Accurate results can be obtained for 2-6 electron systems.Running time: A couple of hours for a typical system.     

Real-time Java simulations of multiple interference dielectric filters

An interactive Java applet for real-time simulation and visualization of the transmittance properties of multiple interference dielectric filters is presented. The most commonly used interference filters as well as the state-of-the-art ones are embedded in this platform-independent applet which can serve research and education purposes. The Transmittance applet can be freely downloaded from the site http://cpc.cs.qub.ac.uk.

Program summary

Program title: TransmittanceCatalogue identifier: AEBQ_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEBQ_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 5778No. of bytes in distributed program, including test data, etc.: 90 474Distribution format: tar.gzProgramming language: JavaComputer: Developed on PC-Pentium platformOperating system: Any Java-enabled OS. Applet was tested on Windows ME, XP, Sun Solaris, Mac OSRAM: VariableClassification: 18Nature of problem: Sophisticated wavelength selective multiple interference filters can include some tens or even hundreds of dielectric layers. The spectral response of such a stack is not obvious. On the other hand, there is a strong demand from application designers and students to get a quick insight into the properties of a given filter.Solution method: A Java applet was developed for the computation and the visualization of the transmittance of multilayer interference filters. It is simple to use and the embedded filter library can serve educational purposes. Also, its ability to handle complex structures will be appreciated as a useful research and development tool.Running time: Real-time simulations