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Quantemol
Quantemol Ltd is based in University College London initiated by Professor Jonathan Tennyson FRS and Dr. Daniel Brown in 2004. The company initially developed a unique software tool, Quantemol-N, which provides full accessibility to the highly sophisticated UK molecular R-matrix codes, used to model electron polyatomic molecule interactions. Since then Quantemol has widened to further types of simulation, with plasmas and industrial plasma tools, in Quantemol-VT in 2013 and launched in 2016 a sustainable database Quantemol-DB, representing the chemical and radiative transport properties of a wide range of plasmas. Quantemol-N The Quantemol-N software system has been developed to simplify use of UK R-matrix codes. It provides an interface for non specialists to perform ab initio electron-molecule scattering calculations. Quantemol-N calculates a variety of observables for electron molecule collisions including: * Elastic cross sections * Electronic excitation cross section ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UK Molecular R-matrix Codes
The UK Molecular R-Matrix codes are a set of software routines used to calculate the effects of collision of electrons with atoms and molecules. The R-matrix method is used in computational quantum mechanics to study scattering of positrons and electrons by atomic and molecular targets. The fundamental idea was originally introduced by Eugene Wigner and Leonard Eisenbud in the 1940s. The method works by fixed nuclei approximation, where the molecule's nuclei are considered fixed when collision occurs and the electronic part of the problem is solved. This information is then plugged into calculations which take into account nuclear motion. The UK Molecular R-Matrix codes were developed by the Collaborative Computational Project Q (CCPQ). Software The CCPQ and CCP2 have supported various incarnations of the UK Molecular R-matrix project for almost 40 years. The UK Molecular R-Matrix Group is actually a subgroup of CCP2, and their codes are maintained by Professor Jonathan Tennyson ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOLPRO
MOLPRO is a software package used for accurate ''ab initio'' quantum chemistry calculations. It is developed by Peter Knowles at Cardiff University and Hans-Joachim Werner at Universität Stuttgart in collaboration with other authors. The emphasis in the program is on highly accurate computations, with extensive treatment of the electron correlation problem through the multireference configuration interaction, coupled cluster Coupled cluster (CC) is a numerical technique used for describing many-body systems. Its most common use is as one of several post-Hartree–Fock ab initio quantum chemistry methods in the field of computational chemistry, but it is also used ... and associated methods. Integral-direct local electron correlation methods reduce the increase of the computational cost with molecular size. Accurate ab initio calculations can then be performed for larger molecules. With new explicitly correlated methods the basis set limit can be very closely approached. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jonathan Tennyson (physicist)
Charles Jonathan Penrose Tennyson (born 11 May 1955) is a British physicist. He is the Harrie Massey, Massey Professor of Physics (since 2005) and Head of department at the Department of Physics and Astronomy, University College London (2004–11). Chief Scientist Quantemol Ltd and chair, Blue Skies Space Ltd. Education He was educated at Bootham School, York. He continued his studies at King's College, Cambridge and the University of Sussex. Research and career Tennyson is an author of over 700 scientific papers focusing on applications of molecular spectroscopy to problems in astrophysics, atmospheric science, plasma physics and other fields. He has written a number of popular science articles. He wrote the undergraduate textbook ''Astronomical Spectroscopy: An Introduction to the Atomic and Molecular Physics of Astronomical Spectra'' (2005). Leader of the ExoMol project. Awards and honours Tennyson was elected a List of Fellows of the Royal Society elected in 2009, Fel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Q-Chem
Q-Chem is a general-purpose electronic structure package featuring a variety of established and new methods implemented using innovative algorithms that enable fast calculations of large systems on various computer architectures, from laptops and regular lab workstations to midsize clusters and HPCC, using density functional and wave-function based approaches. It offers an integrated graphical interface and input generator; a large selection of functionals and correlation methods, including methods for electronically excited states and open-shell systems; solvation models; and wave-function analysis tools. In addition to serving the computational chemistry community, Q-Chem also provides a versatile code development platform. History Q-Chem software is maintained and distributed by Q-Chem, Inc., located in Pleasanton, California, USA. It was founded in 1993 as a result of disagreements within the Gaussian company that led to the departure (and subsequent "banning") of John Pople a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PQS (chemical)
PQS is a general purpose quantum chemistry program. Its roots go back to the first ab initio gradient program developed in Professor Peter Pulay's group but now it is developed and distributed commercially by Parallel Quantum Solutions. There is a reduction in cost for academic users and a site license. Its strong points are geometry optimization, nuclear magnetic resonance, NMR chemical shift calculations, and large Møller–Plesset perturbation theory, MP2 calculations, and high parallel efficiency on computing clusters. It includes many other capabilities including Density functional theory, the Computational chemistry#Semiempirical methods, semiempirical methods, MINDO/3, MNDO, Austin Model 1, AM1 and PM3 (chemistry), PM3, Molecular mechanics using the SYBYL 5.0 Force field (chemistry), Force Field, the quantum mechanics/molecular mechanics mixed method using the ONIOM method, natural bond orbital (NBO) analysis and COSMO solvation models. Recently, a highly efficient parallel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GAMESS
GAMESS is a computational chemistry software program and stands for General Atomic and Molecular Electronic Structure System. The original Quantum Chemistry Program Exchange (QCPE) code of GAMESS split in 1981 and now the three version differ considerably: * GAMESS (UK), a fork of the General Atomic and Molecular Electronic Structure System computational chemistry software program * GAMESS (US), a fork of the General Atomic and Molecular Electronic Structure System computational chemistry software program * Firefly (computer program) Firefly, formerly named PC GAMESS, is an ab initio computational chemistry program for Intel-compatible x86, x86-64 processors based on GAMESS (US) sources. However, it has been mostly rewritten (60-70% of the code), especially in platform-sp ... or PC GAMESS, an ab initio computational chemistry program based on GAMESS (US) sources Computational chemistry software {{chem-software-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Scattering
Electron scattering occurs when electrons are deviated from their original trajectory. This is due to the electrostatic forces within matter interaction or, if an external magnetic field is present, the electron may be deflected by the Lorentz force. This scattering typically happens with solids such as metals, semiconductors and insulators; and is a limiting factor in integrated circuits and transistors. The application of electron scattering is such that it can be used as a high resolution microscope for hadronic systems, that allows the measurement of the distribution of charges for nucleons and nuclear structure. The scattering of electrons has allowed us to understand that protons and neutrons are made up of the smaller elementary subatomic particles called quarks. Electrons may be scattered through a solid in several ways: *Not at all: no electron scattering occurs at all and the beam passes straight through. *Single scattering: when an electron is scattered just once. *P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxwellian Distribution
* Maxwell–Boltzmann distribution In physics (in particular in statistical mechanics), the Maxwell–Boltzmann distribution, or Maxwell(ian) distribution, is a particular probability distribution named after James Clerk Maxwell and Ludwig Boltzmann. It was first defined and use ... * The Maxwellians (1991 book) See also * List of things named after James Clerk Maxwell {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CP2K
CP2K is a freely available ( GPL) quantum chemistry and solid state physics program package, written in Fortran 2008, to perform atomistic simulations of solid state, liquid, molecular, periodic, material, crystal, and biological systems. It provides a general framework for different methods: density functional theory (DFT) using a mixed Gaussian and plane waves approach (GPW) via LDA, GGA, MP2, or RPA levels of theory, classical pair and many-body potentials, semi-empirical ( AM1, PM3, MNDO, MNDOd, PM6) and tight-binding Hamiltonians, as well as Quantum Mechanics/Molecular Mechanics (QM/MM) hybrid schemes relying on the Gaussian Expansion of the Electrostatic Potential (GEEP). The Gaussian and Augmented Plane Waves method (GAPW) as an extension of the GPW method allows for all-electron calculations. CP2K can do simulations of molecular dynamics, metadynamics, Monte Carlo, Ehrenfest dynamics, vibrational analysis, core level spectroscopy, energy minimization, and transition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University College London
, mottoeng = Let all come who by merit deserve the most reward , established = , type = Public research university , endowment = £143 million (2020) , budget = £1.544 billion (2019/20) , chancellor = Anne, Princess Royal(as Chancellor of the University of London) , provost = Michael Spence , head_label = Chair of the council , head = Victor L. L. Chu , free_label = Visitor , free = Sir Geoffrey Vos , academic_staff = 9,100 (2020/21) , administrative_staff = 5,855 (2020/21) , students = () , undergrad = () , postgrad = () , coordinates = , campus = Urban , city = London, England , affiliations = , colours = Purple and blue celeste , nickname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaussian (software)
Gaussian is a general purpose computational chemistry software package initially released in 1970 by John Pople and his research group at Carnegie Mellon University as Gaussian 70. It has been continuously updated since then. The name originates from Pople's use of Gaussian orbitals to speed up molecular electronic structure calculations as opposed to using Slater-type orbitals, a choice made to improve performance on the limited computing capacities of then-current computer hardware for Hartree–Fock calculations. The current version of the program is Gaussian 16. Originally available through the Quantum Chemistry Program Exchange, it was later licensed out of Carnegie Mellon University, and since 1987 has been developed and licensed by Gaussian, Inc. Standard abilities According to the most recent Gaussian manual, the package can do: *Molecular mechanics **AMBER **Universal force field (UFF) **DREIDING force field *Semi-empirical quantum chemistry method calculations **Austin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
