Physics

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Monte Carlo methods are used in a diverse number of ways, in the context of molecular computations there are five types most commonly encountered:

  CMC or  "classical" Monte Carlo, samples are drawn from a probability distribution, often the classical Boltzmann distribution, to obtain thermodynamic properties, minimum-energy structures and/or rate coefficients, or perhaps just to sample conformers as part of a global conformer search algorithm.

 

QMC or   "quantum" Monte Carlo, random walks are used to compute quantum-mechanical energies and wave functions, often to solve electronic structure problems, using Schroedinger's equation as a formal starting point.

 

PMC or "path-integral" quantum Monte Carlo, quantum statistical mechanical integrals are computed to obtain thermodynamic properties, or even rate coefficients, using Feynman's path integral as a formal starting point. VMC or  "volumetric" Monte Carlo,random and quasi-random number generators are used to generate molecular volumes and sample molecular phase-space surfaces.

 

SMC or "simulation" Monte Carlostochastic algorithms are used to generate initial conditions for quasi-classical trajectory simulations, or to actually simulate processes using scaling arguments to establish time scales or by introducing stochastic effects into molecular dynamics. "Kinetic Monte Carlo" is an example of an SMC method. So is "thermalization" of a molecular dynamics trajectory.

 

http://www.cooper.edu/engineering/chemechem/monte.html

 

 

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Quantum ESPRESSO is an integrated suite of computer codes for electronic-structure calculations and materials modeling at the nanoscale. It is based on density-functional theory, plane waves, and pseudopotentials (both norm-conserving and ultrasoft).

 

Quantum ESPRESSO stands for opEn Source Package for Research in Electronic Structure, Simulation, and Optimization. It is freely available to researchers around the world under the terms of the GNU General Public License.

 

Quantum ESPRESSO builds onto newly-restructured electronic-structure codes (PWscf, PHONON, CP90, FPMD, Wannier) that have been developed and tested by some of the original authors of novel electronic-structure algorithms - from Car-Parrinello molecular dynamics to density-functional perturbation theory - and applied in the last twenty years by some of the leading materials modeling groups worldwide. Innovation and efficiency is still our main focus.

 

Quantum ESPRESSO is evolving towards a distribution of independent and inter-operable codes in the spirit of an open-source project. Researchers active in the field of electronic-structure calculations are encouraged to participate in the project by contributing their own codes or by implementing their own ideas into existing codes.

 

http://www.quantum-espresso.org/index.php

 

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XFdtd® is a 3D EM simulation software package that provides engineers with powerful and innovative tools for modeling and EM simulation.  It was designed to be simple and easy to use, but with the power to handle the toughest simulations that engineers face today.

Remcom´s MPI module for XFdtd® allows for parallel computations on distributed systems such as Beowulf clusters. In addition to the speed advantages of spreading XFdtd computations over multiple nodes, each node need have only enough memory for its portion of the problem space. Clusters of inexpensive 32 bit machines can handle problems requiring much more than 2 G-Bytes of RAM.

 

Remcom's XStream® Hardware FDTD uses the latest GPGPU Computing technology to provide dramatic speed increases in XFdtd® calculation.  Utilizing the ability of the GPU (Graphics Processing Unit) in modern computer graphics cards to stream floating point calculations, XFdtd achieves extremely fast calculation speeds via the XStream Hardware FDTD option. XStream Hardware FDTD is now based on the NVIDIA Quadro FX 5600 GPU with 1.5 GBytes of accelerated memory.

 

http://www.remcom.com/xf7

 

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