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Desmond (software)
Desmond is a software package developed at D. E. Shaw Research to perform high-speed molecular dynamics simulations of biological systems on conventional computer clusters. The code uses novel parallel algorithms and numerical methods to achieve high performance on platforms containing multiple processors, but may also be executed on a single computer. The core and source code are available at no cost for non-commercial use by universities and other not-for-profit research institutions, and have been used in the Folding@home distributed computing project. Desmond is available as commercial software through Schrödinger, Inc. Molecular dynamics program Desmond supports algorithms typically used to perform fast and accurate molecular dynamics. Long-range electrostatic energy and forces can be calculated using particle mesh Ewald-based methods. Constraints can be enforced using the M-SHAKE algorithm. These methods can be used together with time-scale splitting (RESPA-based) inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which includes the kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name "GNU/Linux" to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian, Fedora Linux, and Ubuntu, the latter of which itself consists of many different distributions and modifications, including Lubuntu and Xubuntu. Commercial distributions include Red Hat Enterprise Linux and SUSE Linux Enterprise. Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma. Distributions intended for ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berendsen Thermostat
The Berendsen thermostat is an algorithm to re-scale the velocities of particles in molecular dynamics simulations to control the simulation temperature. Basic description In this scheme, the system is weakly coupled to a heat bath with some temperature. The thermostat suppresses fluctuations of the kinetic energy of the system and therefore cannot produce trajectories consistent with the canonical ensemble. The temperature of the system is corrected such that the deviation exponentially decays with some time constant \tau . :\frac=\frac Though the thermostat does not generate a correct canonical ensemble (especially for small systems), for large systems on the order of hundreds or thousands of atoms/molecules, the approximation yields roughly correct results for most calculated properties. The scheme is widely used due to the efficiency with which it relaxes a system to some target (bath) temperature. In many instances, systems are initially equilibrated using the Berendsen scheme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Dynamics
Molecular dynamics (MD) is a computer simulation method for analyzing the physical movements of atoms and molecules. The atoms and molecules are allowed to interact for a fixed period of time, giving a view of the dynamic "evolution" of the system. In the most common version, the trajectories of atoms and molecules are determined by numerically solving Newton's equations of motion for a system of interacting particles, where forces between the particles and their potential energies are often calculated using interatomic potentials or molecular mechanical force fields. The method is applied mostly in chemical physics, materials science, and biophysics. Because molecular systems typically consist of a vast number of particles, it is impossible to determine the properties of such complex systems analytically; MD simulation circumvents this problem by using numerical methods. However, long MD simulations are mathematically ill-conditioned, generating cumulative errors in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Design Software
Molecular design software is notable software for molecular modeling, that provides special support for developing molecular models ''de novo''. In contrast to the usual molecular modeling programs, such as for molecular dynamics and quantum chemistry, such software ''directly'' supports the aspects related to constructing molecular models, including: * Molecular graphics * interactive molecular drawing and conformational editing * building polymeric molecules, crystals, and solvated systems * partial charges development * geometry optimization * support for the different aspects of force field development Comparison of software covering the major aspects of molecular design Notes and references See also {{columns-list, colwidth=30em, *Molecule editor *Molecular modelling *Molecular modeling on GPUs *Protein design *Drug design *Force field (chemistry) *Comparison of force field implementations *Comparison of nucleic acid simulation software *Comparison of software for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metadynamics
Metadynamics (MTD; also abbreviated as METAD or MetaD) is a computer simulation method in computational physics, chemistry and biology. It is used to estimate the free energy and other state functions of a system, where ergodicity is hindered by the form of the system's energy landscape. It was first suggested by Alessandro Laio and Michele Parrinello in 2002 and is usually applied within molecular dynamics simulations. MTD closely resembles a number of recent methods such as adaptively biased molecular dynamics, adaptive reaction coordinate forces and local elevation umbrella sampling. More recently, both the original and well-tempered metadynamics were derived in the context of importance sampling and shown to be a special case of the adaptive biasing potential setting. MTD is related to the Wang–Landau sampling. Introduction The technique builds on a large number of related methods including (in a chronological order) the deflation, tunneling, tabu search, local elevation, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Software For Molecular Mechanics Modeling
This is a list of computer programs that are predominantly used for molecular mechanics calculations. See also *Car–Parrinello molecular dynamics *Comparison of force-field implementations *Comparison of nucleic acid simulation software *List of molecular graphics systems *List of protein structure prediction software *List of quantum chemistry and solid-state physics software * List of software for Monte Carlo molecular modeling * List of software for nanostructures modeling *Molecular design software *Molecular dynamics *Molecular modeling on GPUs *Molecule editor A molecule editor is a computer program for creating and modifying representations of chemical structures. Molecule editors can manipulate chemical structure representations in either a simulated two-dimensional space or three-dimensional space, v ... Notes and references External linksSINCRIS [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Molecular Dynamics
Visual Molecular Dynamics (VMD) is a molecular modelling and visualization computer program. VMD is developed mainly as a tool to view and analyze the results of molecular dynamics simulations. It also includes tools for working with volumetric data, sequence data, and arbitrary graphics objects. Molecular scenes can be exported to external rendering tools such as POV-Ray, RenderMan, Tachyon, Virtual Reality Modeling Language (VRML), and many others. Users can run their own Tcl and Python scripts within VMD as it includes embedded Tcl and Python interpreters. VMD runs on Unix, Apple Mac macOS, and Microsoft Windows. VMD is available to non-commercial users under a distribution-specific license which permits both use of the program and modification of its source code, at no charge. History VMD has been developed under the aegis of principal investigator Klaus Schulten in the Theoretical and Computational Biophysics group at the Beckman Institute for Advanced Science and Technolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Model
In computational chemistry, a water model is used to simulate and thermodynamically calculate water clusters, liquid water, and aqueous solutions with explicit solvent. The models are determined from quantum mechanics, molecular mechanics, experimental results, and these combinations. To imitate a specific nature of molecules, many types of models have been developed. In general, these can be classified by the following three points; (i) the number of interaction points called ''site'', (ii) whether the model is rigid or flexible, (iii) whether the model includes polarization effects. An alternative to the explicit water models is to use an implicit solvation model, also termed a continuum model, an example of which would be the COSMO solvation model or the polarizable continuum model (PCM) or a hybrid solvation model. Simple water models The rigid models are considered the simplest water models and rely on non-bonded interactions. In these models, bonding interactions are imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OPLS
The OPLS (Optimized Potentials for Liquid Simulations) force field was developed by Prof. William L. Jorgensen at Purdue University and later at Yale University. Functional form The functional form of the OPLS force field is very similar to that of AMBER: E \left(r^N \right ) = E_\mathrm + E_\mathrm + E_\mathrm + E_\mathrm E_\mathrm = \sum_\mathrm K_r (r-r_0)^2 \, E_\mathrm = \sum_\mathrm k_\theta (\theta-\theta_0)^2 \, E_\mathrm = \sum_\mathrm \left( \frac \left 1 + \cos (\phi-\phi_1) \right + \frac \left 1 - \cos (2\phi-\phi_2) \right + \frac \left 1 + \cos (3\phi-\phi_3) \right + \frac \left 1 - \cos (4\phi-\phi_4) \right \right) E_\mathrm = \sum_ f_ \left( \frac - \frac + \frac \right) with the combining rules A_ = \sqrt and C_ = \sqrt. Intramolecular nonbonded interactions E_\mathrm are counted only for atoms three or more bonds apart; 1,4 interactions are sca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AMBER
Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In Maxine N. Lurie and Marc Mappen (eds.) ''Encyclopedia of New Jersey'', Rutgers University Press, . Amber is used in jewelry and has been used as a healing agent in folk medicine. There are five classes of amber, defined on the basis of their chemical constituents. Because it originates as a soft, sticky tree resin, amber sometimes contains animal and plant material as inclusions. Amber occurring in coal seams is also called resinite, and the term ''ambrite'' is applied to that found specifically within New Zealand coal seams. Etymology The English word ''amber'' derives from Arabic (ultimately from Middle Persian ''ambar'') via Middle Latin ''ambar'' and Middle French ''ambre''. The word was adopted in Middle English in the 14th century ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CHARMM
Chemistry at Harvard Macromolecular Mechanics (CHARMM) is the name of a widely used set of force fields for molecular dynamics, and the name for the molecular dynamics simulation and analysis computer software package associated with them. The CHARMM Development Project involves a worldwide network of developers working with Martin Karplus and his group at Harvard to develop and maintain the CHARMM program. Licenses for this software are available, for a fee, to people and groups working in academia. Force fields The CHARMM force fields for proteins include: united-atom (sometimes termed ''extended atom'') CHARMM19, all-atom CHARMM22 and its dihedral potential corrected variant CHARMM22/CMAP, as well as later versions CHARMM27 and CHARMM36 and various modifications such as CHARMM36m and CHARMM36IDPSFF. In the CHARMM22 protein force field, the atomic partial charges were derived from quantum chemical calculations of the interactions between model compounds and water. Furthermor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Processing Unit
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and input/output (I/O) operations specified by the instructions in the program. This contrasts with external components such as main memory and I/O circuitry, and specialized processors such as graphics processing units (GPUs). The form, design, and implementation of CPUs have changed over time, but their fundamental operation remains almost unchanged. Principal components of a CPU include the arithmetic–logic unit (ALU) that performs arithmetic and logic operations, processor registers that supply operands to the ALU and store the results of ALU operations, and a control unit that orchestrates the fetching (from memory), decoding and execution (of instructions) by directing the coordinated operations of the ALU, registers and other co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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