Atomistix Virtual NanoLab (VNL) is a commercial point-and-click software for simulation and analysis of physical and chemical properties of nanoscale devices. Virtual NanoLab is developed and sold commercially by QuantumWise A/S. [1] QuantumWise was then acquired by Synopsys in 2017. [2]
With its graphical interface, Virtual NanoLab provides a user-friendly approach to atomic-scale modeling. The software contains a set of interactive instruments that allows the user to design nanosystems, to set up and execute numerical calculations, and to visualize the results. Samples such as molecules, nanotubes, crystalline systems, and two-probe systems (i.e. a nanostructure coupled to two electrodes) are built with a few mouse clicks.
Virtual NanoLab contains a 3D visualization tool, the Nanoscope, where atomic geometries and computed results can be viewed and analyzed. One can for example plot Bloch functions of nanotubes and crystals, molecular orbitals, electron densities, and effective potentials. The numerical engine that carries out the actual simulations is Atomistix ToolKit, which combines density functional theory and non-equilibrium Green's functions to ab initio electronic-structure and transport calculations. Atomistix ToolKit is developed from the academic codes TranSIESTA [3] and McDCal. [4]
The Wannier functions are a complete set of orthogonal functions used in solid-state physics. They were introduced by Gregory Wannier in 1937. Wannier functions are the localized molecular orbitals of crystalline systems.
PLATO is a suite of programs for electronic structure calculations. It receives its name from the choice of basis set used to expand the electronic wavefunctions.
SIESTA is an original method and its computer program implementation, to efficiently perform electronic structure calculations and ab initio molecular dynamics simulations of molecules and solids. SIESTA uses of strictly localized basis sets and from the implementation of linear-scaling algorithms. Accuracy and speed can be tuned in a wide range, from quick exploratory calculations to highly accurate simulations matching the quality of other approaches, such as plane-wave and all-electron methods.
Octopus is a software package for performing Kohn–Sham density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations.
Atomistix A/S was a software company developing tools for atomic scale modelling. It was headquartered in Copenhagen, Denmark, with a subsidiary for Asia Pacific in Singapore and for the Americas in California. In September 2008 Atomistix A/S went bankrupt, but in December 2008 the newly founded company QuantumWise announced that they had acquired all assets from the Atomistix estate and would continue the development and marketing of the products Atomistix ToolKit and Atomistix Virtual NanoLab. QuantumWise was then acquired by Synopsys in 2017.
Marvin Lou Cohen is an American theoretical physicist. He is a University Professor of Physics at the University of California, Berkeley. Cohen is a leading expert in the field of Condensed Matter Physics. He is highly cited and most widely known for his seminal work on the electronic structure of solids.
Volker Heine FRS is a New Zealand / British physicist. He is married to Daphne and they have three children. Volker Heine is considered a pioneer of theoretical and computational studies of the electronic structure of solids and liquids and the determination of physical properties derived from it.
Atomistix ToolKit (ATK) is a commercial software for atomic-scale modeling and simulation of nanosystems. The software was originally developed by Atomistix A/S, and was later acquired by QuantumWise following the Atomistix bankruptcy. QuantumWise was then acquired by Synopsys in 2017.
NanoLanguage is a scripting interface built on top of the interpreted programming language Python, and is primarily intended for simulation of physical and chemical properties of nanoscale systems.
Electron beam ion trap (EBIT) is an electromagnetic bottle that produces and confines highly charged ions. An EBIT uses an electron beam focused with a powerful magnetic field to ionize atoms to high charge states by successive electron impact.
Steven R. White is a professor of physics at the University of California, Irvine. He graduated from the University of California, San Diego; he then received his Ph.D. at Cornell University, where he was a shared student with Kenneth Wilson and John Wilkins. He is most known for inventing the Density Matrix Renormalization Group (DMRG) in 1992. This is a numerical variational technique for high accuracy calculations of the low energy physics of quantum many-body systems. His over one hundred seventy papers on this and related subjects have been used and cited widely—his most cited article has received about four thousand citations.
The reactive empirical bond-order (REBO) model is a function for calculating the potential energy of covalent bonds and the interatomic force. In this model, the total potential energy of system is a sum of nearest-neighbour pair interactions which depend not only on the distance between atoms but also on their local atomic environment. A parametrized bond order function was used to describe chemical pair bonded interactions.
In materials science, the threshold displacement energy is the minimum kinetic energy that an atom in a solid needs to be permanently displaced from its site in the lattice to a defect position. It is also known as "displacement threshold energy" or just "displacement energy". In a crystal, a separate threshold displacement energy exists for each crystallographic direction. Then one should distinguish between the minimum and average over all lattice directions' threshold displacement energies. In amorphous solids, it may be possible to define an effective displacement energy to describe some other average quantity of interest. Threshold displacement energies in typical solids are of the order of 10-50 eV.
David Matthew Ceperley is a theoretical physicist in the physics department at the University of Illinois Urbana-Champaign or UIUC. He is a world expert in the area of Quantum Monte Carlo computations, a method of calculation that is generally recognised to provide accurate quantitative results for many-body problems described by quantum mechanics.
Yambo is a computer software package for studying many-body theory aspects of solids and molecule systems. It calculates the excited state properties of physical systems from first principles, e.g., from quantum mechanics law without the use of empirical data. It is an open-source software released under the GNU General Public License (GPL). However the main development repository is private and only a subset of the features available in the private repository are cloned into the public repository and thus distributed.
David R. Nelson is an American physicist, and Arthur K. Solomon Professor of Biophysics, at Harvard University.
Radiative Auger effect is a decay channel of an inner-shell atomic vacancy state, in which an x-ray photon is emitted accompanying simultaneous promotion of an electron into either a bound or a continuum state. Thus the transition energy is shared between the photon and the electron. The effect was first observed by F. Bloch and P. A. Ross, with initial theoretical explanation by F. Bloch. Later the effect has also been observed on defects in the solid-state, semiconductor quantum emitters, as well as two-dimensional electron gases. In the latter case, the effect is typically referred to as shake-up.
Scissors Modes are collective excitations in which two particle systems move with respect to each other conserving their shape. For the first time they were predicted to occur in deformed atomic nuclei by N. LoIudice and F. Palumbo, who used a semiclassical Two Rotor Model, whose solution required a realization of the O(4) algebra that was not known in mathematics. In this model protons and neutrons were assumed to form two interacting rotors to be identified with the blades of scissors. Their relative motion (Fig.1) generates a magnetic dipole moment whose coupling with the electromagnetic field provides the signature of the mode.
Interatomic potentials are mathematical functions to calculate the potential energy of a system of atoms with given positions in space. Interatomic potentials are widely used as the physical basis of molecular mechanics and molecular dynamics simulations in computational chemistry, computational physics and computational materials science to explain and predict materials properties. Examples of quantitative properties and qualitative phenomena that are explored with interatomic potentials include lattice parameters, surface energies, interfacial energies, adsorption, cohesion, thermal expansion, and elastic and plastic material behavior, as well as chemical reactions.