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Q (software)
Q is a computer software package for molecular dynamics (MD) simulation (current release: Q6). Unlike other MD codes, it has specialized since its conception (Marelius et al. 1998) on three specific types of free energy calculations. These calculations are based on the methods: '' empirical valence bond'' (EVB), ''free energy perturbation'' (FEP), and ''linear interaction energy'' (LIE), as well as, more recently, also path integral calculations using the bisection quantum classical path (BQCP) approach. The methods in which the program specializes can return quantitative calculations of the energy balance which occurs in proteins and nucleic acids. It can provide insight into key problems in biochemistry such as, energetic details on parts of the translation mechanism in mitochondrial ribosomes (Lind et al. 2013), or details in enzymatic reactions (Mones et al. 2013), among others. The program is similar to GROMACS in being force-field agnostic, meaning that it provides no f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uppsala University
Uppsala University ( sv, Uppsala universitet) is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in operation. The university rose to significance during the rise of Swedish Empire, Sweden as a great power at the end of the 16th century and was then given a relative financial stability with a large donation from King Gustavus Adolphus of Sweden, Gustavus Adolphus in the early 17th century. Uppsala also has an important historical place in Swedish national culture, identity and for the Swedish establishment: in historiography, literature, politics, and music. Many aspects of Swedish academic culture in general, such as the white student cap, originated in Uppsala. It shares some peculiarities, such as the student nation system, with Lund University and the University of Helsinki. Uppsala belongs to the Coimbra Group of European universities a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Force Field Implementations
This is a table of notable computer programs implementing molecular mechanics force fields. See also *Force field (chemistry) * List of software for Monte Carlo molecular modeling *Molecular mechanics *Molecular design software *Molecule editor *Comparison of software for molecular mechanics modeling *Molecular modeling on GPU Molecular modeling on GPU is the technique of using a graphics processing unit (GPU) for molecular simulations. In 2007, NVIDIA introduced video cards that could be used not only to show graphics but also for scientific calculations. These cards ... References {{Reflist Force fields Molecular modelling Software comparisons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NAMD
Nanoscale Molecular Dynamics (NAMD, formerly Not Another Molecular Dynamics Program) is computer software for molecular dynamics simulation, written using the Charm++ parallel programming model. It is noted for its parallel efficiency and is often used to simulate large systems (millions of atoms). It has been developed by the collaboration of the Theoretical and Computational Biophysics Group (TCB) and the Parallel Programming Laboratory (PPL) at the University of Illinois at Urbana–Champaign. It was introduced in 1995 by Nelson ''et al.'' as a parallel molecular dynamics code enabling interactive simulation by linking to the visualization code VMD. NAMD has since matured, adding many features and scaling beyond 500,000 processor cores. NAMD has an interface to quantum chemistry packages ORCA and MOPAC, as well as a scripted interface to many other quantum packages. Together with Visual Molecular Dynamics (VMD) and QwikMD, NAMD's interface provides access to hybrid QM/MM simula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solution (chemistry)
In chemistry, a solution is a special type of homogeneous mixture composed of two or more substances. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. If the attractive forces between the solvent and solute particles are greater than the attractive forces holding the solute particles together, the solvent particles pull the solute particles apart and surround them. These surrounded solute particles then move away from the solid solute and out into the solution. The mixing process of a solution happens at a scale where the effects of chemical polarity are involved, resulting in interactions that are specific to solvation. The solution usually has the state of the solvent when the solvent is the larger fraction of the mixture, as is commonly the case. One important parameter of a solution is the concentration, which is a measure of the amount of solute in a given amount of solution or solvent. The term "aqueous solution" is used when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvent
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners (toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers (hexane, petrol ether); in detergents ( citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemical syn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatics
Electrostatics is a branch of physics that studies electric charges at rest (static electricity). Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber, (), was thus the source of the word 'electricity'. Electrostatic phenomena arise from the forces that electric charges exert on each other. Such forces are described by Coulomb's law. Even though electrostatically induced forces seem to be rather weak, some electrostatic forces are relatively large. The force between an electron and a proton, which together make up a hydrogen atom, is about 36 orders of magnitude stronger than the gravitational force acting between them. There are many examples of electrostatic phenomena, from those as simple as the attraction of plastic wrap to one's hand after it is removed from a package, to the apparently spontaneous explosion of grain silos, the damage of electronic components during manufacturin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Van Der Waals Force
In molecular physics, the van der Waals force is a distance-dependent interaction between atoms or molecules. Unlike ionic or covalent bonds, these attractions do not result from a chemical electronic bond; they are comparatively weak and therefore more susceptible to disturbance. The van der Waals force quickly vanishes at longer distances between interacting molecules. Named after Dutch physicist Johannes Diderik van der Waals, the van der Waals force plays a fundamental role in fields as diverse as supramolecular chemistry, structural biology, polymer science, nanotechnology, surface science, and condensed matter physics. It also underlies many properties of organic compounds and molecular solids, including their solubility in polar and non-polar media. If no other force is present, the distance between atoms at which the force becomes repulsive rather than attractive as the atoms approach one another is called the van der Waals contact distance; this phenomenon resul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GROMOS
GROningen MOlecular Simulation (GROMOS) is the name of a force field for molecular dynamics simulation, and a related computer software package. Both are developed at the University of Groningen, and at the Computer-Aided Chemistry Group at the Laboratory for Physical Chemistry at the Swiss Federal Institute of Technology (ETH Zurich). At Groningen, Herman Berendsen was involved in its development. The united atom force field was optimized with respect to the condensed phase properties of alkanes. Versions GROMOS87 Aliphatic and aromatic hydrogen atoms were included implicitly by representing the carbon atom and attached hydrogen atoms as one group centered on the carbon atom, a united atom force field. The van der Waals force parameters were derived from calculations of the crystal structures of hydrocarbons, and on amino acids using short (0.8 nm) nonbonded cutoff radii. GROMOS96 In 1996, a substantial rewrite of the software package was released. The force fiel ... [...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] |
