Feature List

• Electronic Structure & Transport Methods
  • Common Electronic Structure Method Features
  • LCAO Density Functional Theory (DFT)
  • Plane-Wave Density Functional Theory (DFT)
  • Many-Body Perturbation Theory: GW
  • Semiempirical Methods
  • Poisson Equation Solvers
  • Implicit Solvent Model (COSMO)
  • Green's Function Method
• Ion Dynamics
  • Advanced Ion Dynamics Workflows
  • Conventional Force Fields
  • Machine-Learned Force Fields
  • Polymer Simulations
• Physical Property Analysis
  • Electronic Structure
  • Optical & Electro-optical
  • Magnetic & Spin
  • Thermo-Mechanical
  • Electron-Phonon Interaction
  • Composite & Multiscale Workflows
  • NanoLab GUI
• Platform & Infrastructure
  • Python Scripting & Automatization
  • Parallelization & Other Performance Options
• Learn More about QuantumATK

Electronic Structure & Transport Methods

Common Electronic Structure Method Features

Underlying support for the DFT-LCAO, DFT-PlaneWave, GW and Semiempirical methods, as is relevant for each method.

• Norm-conserving Troullier-Martins pseudopotentials
  • Fully relativistic PseudoDojo and SG15 potentials provided for most elements of the periodic table, including semi-core potentials for many elements
  • Non-relativistic FHI potentials with small cores for fast calculations
• Over 400 LDA/GGA/MGGA exchange-correlation functionals via libXC
  • Includes MetaGGA TB09, SCAN and r²SCAN functionals
  • Possibility to add custom functionals
• Hybrid functionals: HSE06, B3LYP, B3LYP5, PBE0
• Dispersion corrections: Grimme D2 and D3 van der Waals models
• Non-collinear, restricted and unrestricted (spin-polarized) calculations
  • Initialization of noncollinear spin calculations from collinear or spin-unpolarized ones for improved convergence, plus custom initial spin-filling schemes
• Spin-orbit coupling
• Brillouin zone sampling k-point grids: Monkhorst-Pack or edge-to-edge zone filling, Gamma-centered or with custom shifts
• Occupation functions: Fermi-Dirac, Methfessel-Paxton, Gaussian, cold smearing
• Initialization of a new calculation via the self-consistent density matrix of a converged one (with automatic spin realignment)
• Charged systems (background compensation charge)
• Simulation of doping via localized atomic core charges)
• Support for inclusion of a homogeneous external electric field in bulk calculations (via constraint)
• Delta test module for benchmark of pseudopotential/basis set accuracy

LCAO Density Functional Theory (DFT)

• Numerical Linear Combination of Atomic Orbital (LCAO) basis sets with compact support
• • Optimized basis sets with low, medium and high accuracy
• Performance options for hybrid functionals
  • Auxiliary Density Matrix Method (ADMM) as memory and performance booster option
  • Linear scaling in number of atoms and k-points
• Dielectric dependent hybrid functional (DDH)
  • Position-dependent exact exchange fraction, automatically calculated from the electron density, extends usability of hybrid functionals to multilayer structures
  • Metallic version for e.g. metal/semiconductor interfaces
• Semiempirical band gap correction methods
  • TB09 MetaGGA functional with adjustable, position-dependent c-parameter
  • DFT+1/2 method
  • Empirical pseudopotential projector shifts
  • Hubbard DFT+U model
    • Dual, on-site, and shell-wise models, with support for spin-polarization
    • Automatic self-consistent ab initio determination of U parameters based on the Locally Screened Coulomb Correction (LSCC) method
• Counterpoise correction for basis set superposition errors (BSSE) for bulk, surface and device (NEGF) configurations
• Ghost atoms (vacuum basis sets) for higher accuracy in the description of surfaces and vacancies
• Virtual crystal approximation (VCA)
• Fractional hydrogen pseudopotentials and basis sets for surface passivation

Plane-Wave Density Functional Theory (DFT)

• Plane-wave basis sets
  • Optimized default mesh cutoff setting for all elements
• Projector-augmented wave (PAW) method
  • GPAW data sets
  • JTH data sets (includes lanthanides)
• Eigensolvers
  • Projected Preconditioned Conjugate Gradient (PPCG) algorithm for better parallel scaling for large systems (default)
  • Generalized Davidson method
• ACE algorithm for hybrid functional calculation
• Initialize plane-wave calculations from an LCAO calculation for faster convergence
• Post-processing like band structure with custom k-points (also with hybrid functionals)
• Fast 1D and 3D k·p method for band structure, density of states, eigenvalues, and optical spectrum calculations without loss of precision, in particular with hybrid functionals

Many-Body Perturbation Theory: GW

• Based on the one-shot perturbative G0W0 method, the most computationally efficient GW approximation
• Uses LCAO basis sets with PARI approximation for much faster calculations compared to PlaneWave basis sets (tested for 100+ atoms)
• Allows for starting from hybrid calculations, i.e., GW@HSE06
• Possibility to run the self-consistent loop and post-processing analysis (band structure, DOS) separately with different k-point sampling

Semiempirical Methods

• DFTB model with over 30 included parameter sets (DFTB2)
• Slater-Koster models, mainly for group IV and III-V semiconductors (including strained systems)
• Extended Hückel model with over 300 built-in basis sets (Hoffmann, Muller, Cerda) for most element in the periodic table
• Interface for definition of user-defined semiempirical models and parameters
• Spin-polarization term can be added via internal database of spin-split parameters
• Support for non-collinear spin and spin-orbit interaction (parameterized)
• Hartree term for self-consistent response to the electrostatic environment
• All models adapted for self-consistent calculations through external database of atomic Hartree terms (following the DFTB approach)
• Ability to handle 1M+ atoms through use of iterative diagonalization solver

Poisson Equation Solvers

• FFT (for periodic systems)
• Multipole expansion (for molecules)
• FFT2D solver (for device configurations that have no metallic and dielectric regions)
• Solvers for systems including metallic/dielectric regions:
  • Multigrid
  • Conjugate gradient method (parallelized in memory and execution)
  • "Direct" solver for large-scale calculations (parallelized in memory)
  • Non-uniform grid solver for bulk systems and devices with vacuum/dielectrics regions in one or both transverse directions
• Dirichlet, von Neumann, or periodic boundary conditions can be specified independently in each direction (also for plane-wave calculations)
• Inclusion of metallic electrodes and dielectric screening regions (in both bulk and device structures) allows for computation of transistor characteristics (gated structures), charge stability diagrams of single-electron transistors, or to apply an electric field across a slab

Implicit Solvent Model (COSMO)

• COSMO (COnductor-like Screening MOdel) model to study solvation effects
  • Solvate molecules, slabs, or one-probe surfaces, and perform geometry optimization and transition state search with DFT-LCAO
  • Compute polarization charges, solvation energies, and wettability/surface wetting, contact angle from Young's law
• COSMO-RS module and GUI analyzer to obtain thermodynamic properties of liquids
  • Built-in database for 1500 molecules
  • Compute acidity (pKa), gas and solid solubility, partition coefficient, vapor pressure, liquid mixture (LLE), sigma plot

Green's Function Method

The unique NEGF transport module in QuantumATK enables studies of nanoscale devices on the atomistic scale at finite bias, in the presence of gates and dielectric screening regions. Transport modeling is supported for LCAO-DFT (LDA, GGA, MetaGGA, HSE06, HSE06-DDH) and Semiempirical methods, and can be performed with inelastic scattering included, as well as finite temperature effects.

• Non-equilibrium Green's function (NEGF) method for two-probe systems
  • NEGF description of the electron distribution in the scattering region, with self-energy coupling to semi-infinite leads (source/drain electrodes)
  • Open boundary conditions (Dirichlet/Dirichlet, Dirichlet/Neumann or Neumann/Neumann) allows application of finite bias between source and drain for calculation of I-V curve
  • Includes all spill-in contributions for density and matrix elements
  • Uses of electronic free energy instead of total energy, as appropriate for open systems
  • Ability to treat systems with different electrodes to enables studies of single interfaces like metal-semiconductor or p-n junctions
  • Ability to add electrostatic gates and dielectric screening regions for transistor characteristics
• Surface Green's function (SGF) method for single surfaces
  • NEGF description of the surface layers, with self-energy coupling to a semi-infinite substrate (replaces the slab approximation with a more physically correct description of surfaces)
  • Appropriate boundary conditions for infinite substrate and infinite vacuum above the surface, both for zero and finite applied bias on the surface
  • Compute surface band structure
• Performance and stability options
  • Scattering states method for fast contour integration in non-equilibrium (finite bias)
  • O(N) Green's function calculation and sparse matrix description of central region
  • Double or single semi-circle contour integration for maximum stability at finite bias
  • Ozaki contour integration to capture deep states
  • Sparse self-energy methods to save memory
  • Store self-energies to disk during calculation (reduce memory) or permanently to reuse in other calculations
  • Adaptive (non-regular) k-point integration for transmission coefficients
  • Multi-level parallelization over self-energies and contour points (combination of transverse k-points and energy points), as well as parallelization of each contour point
  • Minimal electrode concept, where electrodes are automatically repeated in all directions for computing self-energies and to cover a wider central region
• Calculation of I-V curves
  • Elastic, coherent tunneling transport
    • Combined framework for running multiple source-drain/gate voltage calculations and collecting and analyzing the results (I-V curve, on/off ratio, subthreshold slope, transconductance, DIBL, source-drain saturation voltage)
  • Quasi-inelastic and fully inelastic electron-phonon scattering calculations
    • Lowest-order expansion (LOE) and extended LOE (XLOE) approximations for molecular contacts or nanostructures (weak electron-phonon coupling)
    • One-shot self-consistent Born approximation (SCBA) for bulk-like devices (weak, medium, and strong electron-phonon coupling)
    • Inelastic transmission spectrum (IETS) analysis
• PhotoCurrent Module
  • Analysis module for calculating the photon-mediated transmission in a device using first-order perturbation theory within the first Born approximation
  • Also gives the total current based on illumination by the AM1.5 standard solar spectrum
• Geometry optimization protocol for devices, partly based on the Bulk Rigid Relaxation (BRR) method
• Analysis of transport mechanisms
  • Transmission coefficients (k-point/energy resolved)
  • Monkhorst-Pack or edge-to-edge zone filling k-point scheme, with option to carve out only part of the Brillouin zone for detailed information
  • Spectral current
  • Transmission spectrum, eigenvalues, and eigenchannels
  • Device density of states, also projected on atoms and angular momenta
  • Real-space local density of states for band diagram analysis
  • Voltage drop
  • Molecular projected self-consistent Hamiltonian (MPSH) eigenvalues
  • Current density and transmission pathways
  • Tunnel Magneto Resistance (TMR)
  • Spin Transfer Torque (STT) for zero and finite bias, using either a non-selfconsistent approximation or linear response

Ion Dynamics

All simulations described in this section can, with minor limitations, be run with any choice of calculator for obtaining energies, forces, and stress, i.e. using any DFT, semiempirical, or force-field calculator.

• Geometry and unit cell optimization (forces and stress)
  • Quasi-Newton LBFGS and FIRE methods
  • Optimize structure to finite target stress (hydrostatic or tensor)
  • Pre/post step Python hooks for custom on-the-fly analysis
• Phonons
  • Computation of dynamical matrix via numerical Hessian of supercell (frozen phonon method)
  • Automatic suggestion of supercell size
  • Uses crystal symmetries to reduce the number of displacements required
  • Wigner-Seitz approximation for speeding up calculations of large systems (avoid supercell repetition if the cell is already large enough)
• Nudged Elastic Bands (NEB) method
  • Calculation of transition states and reaction pathways
  • Climbing image method with option to converge the forces of the transition state to tighter accuracy than the rest of the NEB path
  • Pre-optimize path using image-dependent pair potential (IDPP) method, or linear interpolation, or Halgren-Lipscomb method
  • Support for varying cell shape and size, to simulate e.g. phase changes
• Molecular Dynamics (MD).
  • Thermostats and barostats:
    • NVE Velocity Verlet
    • NVT Nosé-Hoover with chains
    • NVT/NPT Berendsen
    • NVT Bussi-Donadio-Parrinello stochastic velocity rescaling
    • NPT Martyna-Tobias-Klein barostat
    • Langevin
  • All thermostats and barostats support linear heating and cooling
  • All barostats support isotropic and anisotropic pressure coupling and linear compression
  • Set initial particle velocities via Maxwell-Boltzmann distribution, existing velocities from a previous run, or manual/custom initialization
  • Thermal transport simulations using reverse non-equilibrium MD (RNEMD)
  • Predefined and user-defined pre- and post-step hooks in Python for on-the-fly analysis
    • Kinetic and potential energy, volume, density, temperature, stress, strain, pressure
    • Custom constraints and operations
  • Fine-grained control over saving measured quantities at user-defined intervals
• Support for pre-defined and custom isotopes in all simulations
• Perform geometry optimization, NEB, or MD under an applied homogeneous electric field: Using Born effective charges for DFT or partial charges for force fields
• Constraints
  • Fix atoms fully, or only in X/Y/Z
  • Fix center of mass
  • Constrain Bravais lattice type (even when target stress is applied)
  • Fix space group (geometry optimization)
  • Constant volume optimization (geometry optimization)
  • Fix specific bond length and angles

Advanced Ion Dynamics Workflows

• Global optimization: Genetic algorithm for crystal structure prediction with custom fitness criteria
• Time-stamped Force-bias Monte Carlo (TFMC)
  • Alternative to molecular dynamics for long time-scale equilibration, deposition, amorphization, diffusion, sampling of rare events, etc., either at constant temperature with a linear heating/cooling ramp or constant pressure
  • Support for NVT and NPT
• Adaptive Kinetic Monte Carlo (AKMC): Long time scale molecular dynamics for finding unknown reaction mechanisms and estimating reaction rates
• Harmonic Transition State Theory (HTST) analysis of transition rates
• Metadynamics, implemented via the PLUMED library
• Special Thermal Displacement method: Include temperature effects on band structure, dielectric constant, NEGF transmission (current), and other quantities
• Steered MD simulations to model crystallization in bulk and interface materials: Uses a slowly moving bias potential drive an amorphous system into a crystal state, using the isotropic x-ray diffraction (XRD) peak as a collective variable (reaction coordinate)

Conventional Force Fields

• Over 400 empirical classical potentials included
  • Two/three-body potentials: Lennard-Jones (various versions), Coulomb (various versions),
  • Stillinger-Weber, Tersoff (various versions), Brenner, Morse, Buckingham, Vessal, Tosi-Fumi, user-defined tabulated
  • Many-body: EAM, MEAM, Finnis-Sinclair, Sutton-Chen, charge-optimized many-body (COMB)
  • Polarizable: Madden/Tangney-Scandolo, core-shell
  • ReaxFF
  • Valence Force Field (VFF) models
  • Brenner/REBO and Moliere potentials
  • Universal Force Field (UFF) with parameters for most of periodic table
  • Bonded DREIDING, OPLS-AA, OPLS-Min and UFF for polymer, battery electrolyte and organic molecule simulations
• Incorporate partial charges into potentials to account for (long-range) electrostatic interactions: Replicate electrostatic interactions from DFT calculations, estimated by QEq, D4-EEQ, or manually assigned
• BYOP (Bring Your Own Potential)
• Python and GUI interface for adding literature potentials of any of the supported types
• GUI to set up organic force fields (OPLS, UFF, Dreiding) and combine it with inorganic force fields for surfaces and non-particles
• Support for custom combinations of potentials
  • E.g. combine a Stillinger-Weber potential with a Lennard-Jones term to account for van der Waals interaction
  • Several such potentials from literature are already provided: Pedone, Guillot-Sator, Marian-Gastreich, Feuston-Garofalini, Matsui, Leinenweber, and more

Machine-Learned Force Fields

• Library of pre-trained Moment Tensor Potentials (MTP) for bulk crystals, amorphous, alloy materials, interfaces, and surface process simulations [LINK TO LIST OF INCLUDED POTENTIALS]
• M3GNet universal graph deep learning interatomic potential for the whole periodic table (MP-2021.2.8-PES and MP-2021.2.8-DIRECT-PES)
• Framework for fitting custom MTPs
  • Automatic generation of training configurations for:
    • Crystal and amorphous bulk materials
    • Interfaces
    • Molecules
    • Alloy materials
  • Element-specific global parameters allowing for better accuracy of multi-element MTPs
  • Active Learning: Improve initial MTP by automatically adding extrapolating configurations to the training set and re-training on the fly during MD, NEB, geometry optimization, and crystal structure prediction (using query-by-committee extrapolation grade)
  • GUI templates for fitting protocols, plus interactive analyzer to assess the precision and accuracy of trained MTP
• Combine MTPs with additional interactions to improve overall accuracy in specific applications
  • Long-range D3 dispersion correction or electrostatic interactions (QEq)
  • Short-range repulsion (ZBL)

Polymer Simulations

• Monte Carlo builder for thermoplasts to efficiently build high-quality polymer melts or composite structures without long brute-force equilibration MD runs
• Reaction tool for building thermoset polymers which form cross-linked or 3D network structures, as well as rubber-like network structures
• Support for homo- and co-polymers, and polymer blends
• Include additive molecules, surfaces, nanoparticles, or any nanostructure
• Create your own monomers or use provided monomers from monomer database, add monomers in forward or reverse orientations
• Automatic assignment of connectivity tags to define monomer linking reactions
• Automatic potential generation for DREIDING, UFF and OPLS-AA
• Several polymer equilibration methods, such as
  • Force-capped-equilibration for initial equilibration
  • Singe-chain mean-field (SCMF) equilibration
  • Energy minimization for relaxing the polymer system
  • Custom 21-step polymer equilibration automatic workflow
• Support for united atoms and coarse-grained polymers to significantly speed up simulations
• Analysis tools
  • Plotting end-to-end distances, free-volume, characteristic ratio, molecular order parameters, radius of gyration
  • Glass transition analyzer, and tools for plotting stress-strain curves

Physical Property Analysis

All properties listed within these sections can be computed with DFT-LCAO, while several of them can also be calculated using plane-wave DFT and semiempirical methods. Those only related to total energies, forces and stress can additionally be extracted from force field simulations. It is furthermore possible to seamlessly combine DFT/semiempirical (for the electronic part) with a force field (for the ionic degrees of freedom), where relevant (for example, for electro-optical tensors).

Electronic Structure

• Band structure
  • User-defined Brillouin zone path through selection of predefined high symmetry points
  • Projections onto atoms, spin, orbitals, or angular momenta, in any desired combination
  • Fat band structure (indicating contributions of projections)
  • Effective band structure, i.e. unfolding of band structure for alloys and other supercells back to primitive cell, with possibility to include defects in the supercell
  • Local band structure
• Molecular spectrum
  • One-electron spectrum of molecules
  • Projected Gamma-point molecular spectrum for periodic systems
• Density of states (DOS)
  • Calculated using the tetrahedron method or Gaussian smearing (for few k-points)
  • Projection onto atoms, spin, orbitals, or angular momenta, in any desired combination
• Carrier concentration (from DOS and Fermi distribution)
• Mulliken populations of atoms, bonds, and orbitals
• Real-space 3D grid quantities
  • Electron density
  • Effective potential
  • Full Hartree or Hartree difference potential
  • Exchange-correlation potential
  • Full electrostatic or electrostatic difference potential
  • Electron localization function (ELF)
  • Molecular orbitals
  • Bloch functions, complex wavefunction with phase information
  • Spatially resolved local density of states (projection of total DOS on atomic orbitals)
  • Partial electron density (projected in an energy range and/or band indices, and by k-points)
  • All quantities are represented as Python objects allowing for manipulations and combinations, or evaluation at arbitrary points in space
• Total/free energy: Optional entropy contribution
• Polarization and piezoelectric tensor
  • Calculated using the Berry phase approach
  • Optional internal ion relaxation
• Effective mass tensor analysis
• Bader charges (plane-wave only)
• Born effective charges
• Electronic inverse participation ratio (IPR)
• Bulk transmission spectrum
• Complex band structure
• Fermi surface

Optical & Electro-optical

• Dielectric properties and infrared spectroscopy (Dielectric tensor analysis object)
  • Static dielectric constant
  • Optical properties, such as refractive indices, extinction coefficients, reflectivity in the THz regime
  • Infrared spectrum, including both electronic and ionic contributions (coupling with vibrations for low frequency)
• Vibrational spectra for liquids and amorphous materials above their glass transition temperatures can be also obtained from molecular dynamics trajectory
• Electro-optical tensor: Total, electronic and ionic tensors, and also ionic part for different modes
• Optical spectrum
  • Both contributions, interband and intraband (dominating in metals due to plasmons)
  • Linear electronic susceptibility, refractive indices, absorption from the Kubo-Greenwood formalism (no ionic contribution)
• Second harmonics generation (SHG) susceptibility: Spin up/spin down, real, imaginary and absolute values for different tensor components
• Polar LO-TO phonon splitting of phonon band structure
• Raman spectrum: Raman tensor, phonon mode intensities and polarization dependent or averaged Raman spectra for incoming light scattered in bulk and 2D materials or nanowires

Magnetic & Spin

• Gilbert damping
  • Damping constant, damping rate, and damping tensor for different life-time broadenings
  • Based on Kambersky’s torque-torque correlation model with a Lorentzian spectral function
• Heisenberg exchange analysis: Empirical approach to studying Heisenberg exchange coupling, exchange stiffness, Curie temperature, magnon band structure, Dzyaloshinskii-Moria interactions, etc
• Magnetic Anisotropy Energy (MAE)
  • Based on the force theorem (not total energy differences which can be numerically unstable)
  • Site/shell/orbital projections
• Orbital moment
• Evaluation of phonon-limited spin life-times
• Nuclear magnetic resonance (NMR)
  • Shielding tensors, isotropic and anisotropic chemical shielding, chemical shifts, electric field gradients and quadrupole coupling constants
  • Based on the GIPAW approach (plane-wave PAW only)

Thermo-Mechanical

• Forces and stress (analytic Hellmann–Feynman for DFT)
• Elastic constants
• Local stress
• Local structure (coordination analysis via centrosymmetry)
• Phonon band structure
• Phonon density of states
• Vibrational inverse participation ratio (IPR)
• Vibration modes
• Zero-point energy
• Free lattice energy
• Vibrational free energy (quasi-harmonic approximation)
• Glass transition temperature
• Shear viscosity
• Export movies of MD trajectories, phonon vibrations, NEB paths, etc., combined with measurements of e.g. total energy
• Partial charge analysis
• Visualization of velocities from MD simulations
• Plot measured quantities along with the MD trajectory as combined animation
• Interactive analysis tool (line, bar, histogram) for MD trajectory and single configuration properties, with possibility to select subset of elements/atoms and overlay multiple quantities in the same plot
  • Angular distribution function
  • Chemical composition profile
  • Coordination number profile
  • Infrared spectrum
  • Ionic conductivity
  • Kinetic energy distribution
  • Mass density profile
  • Mean-square displacement
  • Nearest neighbor number
  • Neutron scattering factor
  • Q Numbers
  • Radial distribution function
  • Self-diffusion
  • Specific heat capacity (based on vibrational DOS)
  • Temperature profile
  • Velocity autocorrelation
  • Velocity distribution
  • Vibrational density of states
  • Void-size distribution
  • X-ray scattering

Electron-Phonon Interaction

• Automated workflows for computing dynamical matrix followed by Hamiltonian derivatives (dH/dR)
• Tetrahedron integration method for calculating mobility and resistivity of non-trivial Fermi surfaces, or direct integration with clever selections of BZ areas
• Approximate methods for calculating phonon-limited resistivity
  • constant mean-free path (for nanostructures)
  • constant relaxation time method (for bulk)
• Output quantities
  • Electron-phonon coupling matrix elements
  • Deformation potentials and conductivity/mobility tensors from the Boltzmann equation, with constant, full k-point dependent and/or only energy-dependent relaxation times
  • Hall coefficient and Hall conductivity tensors
  • Phonon-limited momentum and spin lifetimes for different temperatures, broadenings and bands, resolve different phonon modes contributions
  • Thermal velocity of electrons and holes

Composite & Multiscale Workflows

• Linking atomistic grain boundary scattering (GB) simulations to TCAD (Raphael FX) to evaluate resistivity of alternative metals for advanced logic interconnects by automatically setting up a large set of GB models and extracting the GB resistivity as a function of average grain size using the Mayadas-Shatzkes model
• Linking QuantumATK simulations to TCAD (QTX/Sentaurus Device) to screen different 2D materials for FET performance
• Seebeck coefficients and thermoelectric ZT (and underlying first moment and thermal conductance tensors)
• Interface to Vampire atomistic magnetic simulation code (link to Vampire page)
  • Run micromagnetics simulations using materials parameters based on DFT
  • Visualize and analyze results such as magnetization dynamics, magnetic anisotropy energy, and Curie temperature
• STM images within the Tersoff-Hamann approximation
• Thermochemistry analysis
  • Screen critical chemical reactions for a given process
  • Find ideal reactants, optimal reaction conditions
  • Investigate reaction energetics
  • Pyrolysis simulations to obtain equilibrium composition of species in a gas-phase reaction
• Surface process simulation tools to study deposition (ALD), etching (ALE), and sputtering
  • Interactive setup and analysis tools to study the impact of incoming kinetic energy, incident angle, the time between impacts, surface temperature, and thermostat layer thickness
  • Hybrid MD/Force-bias Monte Carlo simulations to increase accessible time-scale and ensure proper equilibration between deposition events
  • Calculate sputtering yield, sticking coefficient, and precursor coverage needed for feature-scale and reactor-scale models
  • Use pre-trained MTPs for highly efficient simulation with near ab initio accuracy, or employ tailored protocols to train MTPs for new materials and processes
• Defect characterization framework
  • Automatically sets up and runs all calculations required for a comprehensive study of
    • formation energies and trap levels
    • migration paths and energies
    • defect-assisted recombination, i.e., temperature-dependent Shockley-Read-Hall capture rates, and luminescence line shapes
  • Type of defects supported: vacancies, substitutional atoms, interstitial atoms, split interstitials, pairs & larger clusters, ring mechanisms, and more
  • FNV correction scheme for charged defects with automatic Gaussian model charge fitting
  • Possibility to include vibrational corrections and modify atomic chemical potentials
  • Automatically finds symmetrically unique defect pairs
  • Elastic correction to account for spurious residual stress caused by a defect center in a finite supercell of the host material
  • Band gap correction scheme to obtain accurate band gaps for defect trap levels at significantly lower computational cost than using e.g. HSE06 for the whole calculation
  • GUI setup of entire simulation and interactive analyzer to visualize trap levels, formation energies, etc
  • Use the obtained results to further study defect diffusion
  • Automatically finds symmetrically unique diffusion paths between compatible defects/charge states, creates corresponding NEB configurations, optimizes the path, and selects lowest barrier diffusion paths
  • Analyze diffusion network and defect diffusivity in a dedicated GUI tool

NanoLab GUI

• Atomic geometry builder for molecules, crystals, surfaces, nanostructures and devices
  • Interactive control of all aspects of atomistic structures via a large variety of editing tools
    • Insert, delete, edit, repeat, move, sort, translate, wrap, mirror, rotate, align, perturb, stretch atoms/or lattices, and more
    • Select atoms based on query language, tags, geometric shapes, mouse selection, bond lengths, etc.
    • Automatic detection of overlapping/close atoms
    • Cut, copy, paste atoms
    • Unlimited undo (and redo) of operations
  • Z-matrix tool for bond length and angle adjustments of relative fragments
  • Surface cleaver: Interactively build slab, supercell, or surface geometries by selecting Miller indices, surface vectors and cleave planes
  • Interface builder
    • Generate interface configurations based on analysis of strain, supercell size, and relative lattice rotations between two or more materials
    • Pre-optimize structure with classical force fields directly in the tool
  • HKMG/MRAM Builders
    • Automatically build nearly defect-free multilayer stacks of amorphous and crystalline layers of desired thicknesses to generate high-κ metal gate (HKMG) stacks and magnetic tunnel junctions (MTJ)
    • Uses pre-trained Moment Tensor Potentials to rapidly generate DFT-quality multi-layer configurations
  • Crystal builder
    • Build crystals from scratch through space group symmetries and Wyckoff positions
    • Choose from hundreds of built-in templates based on Strukturbericht designations
  • Grain boundary builder
    • Build grain boundaries, based on coincidence site lattice theory
    • Choose between different grain boundary planes and types of grain boundaries (tilt, twist or mixed)
  • Passivation tool to automatically locate and saturate dangling bonds
  • Tools for setting up device and surface structures for NEGF transport and surface Green’s function calculations
    • Add gate electrodes and dielectric screening regions
    • Introduce localized background charges to emulate doping in semiconductors
  • Molecular builder
    • Build up molecular structures by adding atoms, rings, side groups, ligands, etc via a point and click-and-drag interface
    • Edit bond lengths, angles and dihedrals
    • Integrated tool for finding, adding or deleting static bonds
    • On-the-fly or on-demand geometry optimization with a Universal Force Field (UFF)
    • Create molecular structure from SMILES string (optionally with static bonds)
  • Builder plugin for adsorbing molecules on a surface
    • Define surface sites where molecules can be attached, control their density, orientation and distance above the surface
    • Add different molecule types to the same surface
  • Dedicated tools for building nanotubes, nanoribbons, and nanowires
  • Nanoparticle builder: Regular, icosahedrons, or Wulff construction to minimize surface energy
  • Polycrystalline builder based on Voronoi tesselations
  • Builders for amorphous structures and alloys
    • Amorphous pre-builder and Packmol interface to create rough initial guesses for amorphous structures
    • Special Quasi-Random Structures (SQS) algorithm for generating supercell models with a correlation function as close as possible to an ideal alloy
      • Uses a genetic algorithm (unlike other codes that perform an open-ended Monte Carlo simulation, which can be very slow)
      • Supports two-component systems like SixGe1-x or InxGa1-xAs
      • Can be used for any type of geometry, incl. nanowires etc.
    • Substitutional and generic alloy builders, plus specialized Heusler alloy builder
  • Nudged Elastic Band (NEB) setup tool
    • Set up and manipulate NEB paths, using a set of start, end, and (optional) intermediate geometries
    • Edit images collectively or individually (adding/removing/substituting atoms, adjusting a particular image geometry, add intermediate images, etc)
  • Space group symmetry information tool: Option to symmetrize crystal structures based on approximate space groups
  • Tool to compare and edit two structures to match up their atom indexing
  • Force-field optimizer built into the Builder
  • Import/export of most common atomic-scale modeling file formats
    • Embedded version of OpenBabel to support additional formats
    • Extendable by plugins for custom file formats
  • Structures are kept in the Builder stash between sessions and can easily be shared with other users
• Databases
  • Internal structure library with several hundred molecules, crystal structures, zeolites, fullerenes, and monomers
  • Interface to query online databases, with pre-defined support for
    • Crystallography Online Database
    • Materials Project
  • Support for other databases can be added through plugins
  • Interface to create and maintain local MongoDB or MySQL database of structures and calculation results
• Workflow Builder
  • Interactively assemble workflows to set up anything from a simple DFT calculation to advanced flows that combine several methods and results into composite analysis objects
  • Set up all aspects of a calculation using GUI widgets with links to the manual for each parameter
  • Pre-defined workflow templates for multi-stage simulations such as melt-quench MD, MTP training, deposition/etching/sputtering surface process simulations, thermochemistry, defect diffusion
  • Pre-defined and customizable preset calculator settings for general and specific situations (low/high accuracy, metal/semiconductor materials, etc)
  • Build own script blocks using the plugin framework
  • Workflows are stored as objects in HDF5 files for reuse and sharing, and can be exported as Python scripts
  • Set up and submit a large number of simulations at once in parallel for high-throughput materials screening or scanning over computational parameters
  • Results can be collected in tables for batch analysis and plotting
• Job Manager
  • Submit, monitor, cancel, resubmit multiple jobs from the GUI
    • Serial or parallel, locally or to remote machines
    • Control MPI processes vs OpenMPI threading, balance against hardware capacity
  • Automatically copies input and output files to/from remote resources
  • Queue types supported: Torque/PBS, PBSPro, LSF, SLURM, SGE, and direct execution (no queue); additional types can be added by plugins
  • No server-side daemon required, only relies on SSH connection
    • Built-in diagnostics tool to check settings before submitting real jobs
    • Built-in SSH key generation and transfer to remote host
• 3D Data Viewer
  • Isosurfaces, isolines, and contour plots, with graphical repetition and data range control
  • Control atom color, size, transparency, etc.
  • Color atoms by computed quantities, like forces, velocities (also in movies of e.g. MD trajectories)
  • Polyhedral rendering of crystals
  • Voxel plot (point cloud) rendering of 3D grids
  • Vector field plots
  • 3D extrusion of contour planes
  • Brillouin zone visualizer for crystals, with indicated high-symmetry points
  • Export images in most common graphical formats
  • Export (and import) CUBE or simple xyz data files for external plotting
  • Export movies of MD trajectories, phonon vibrations, NEB paths, etc
  • Auto-rotated views can be exported as animated GIFs
  • Interactive 3D measurement tool for distances and angles
  • 3D scene camera and lighting control
• 2D Plot Framework
  • Built-in plotting engine, based on Matplotlib, to visualize results of calculations, like band structures, with a single click
  • Interactive control of color, line width, etc. of multiple items (several bands for instance) at once, plus axis range and labels, legend, grid layout, and more
  • Add annotations like arrows and labels
  • Use dual axes: logarithmic and linear scale, and color code the data to match the particular axis
  • Save customized plots for further analysis and reuse plot setups with new data
  • Link and combine plots, e.g. band structure and DOS in the same plot
  • Fit data to linear, quadratic, and other models, apply smooth rolling or macroscopic averaging
  • Interactively measure distances between data points
  • 2D plot of atomic structures to include in data plots
  • Export plot data to text; import data from text files for direct visualization
  • Export plots as images for publication
  • Build custom plots via Python scripting (Plot Framework API), and apply the same plot settings to multiple calculations
• Project and data management
  • Organize data files into projects which can be transferred between computers and shared with other users
  • Use simple filters or advanced SQL search queries on data and files
  • Report generator tool
    • Extract results from multiple calculations and perform analysis by combining it into a table, grouping the data, and visualizing extracted quantities (for example equation-of-state graph from individual total energy runs)
    • Visualize trends, compare methods, study numerical convergence, etc
    • Create and reuse report protocols to save time when analyzing data from multiple sets of simulations
    • Save results in HDF5, CSV or Excel format

Platform & Infrastructure

QuantumATK is delivered as a self-contained binary installer, with no compilation needed and no external library dependencies beyond standard operating system packages.

• Runs on all modern 64-bit Windows and Linux versions (detailed system requirements)
• Intel MPI is included in the shipment for all platforms, providing support for all modern network fabrics (Ethernet, Infiniband, Myrinet, etc)
• High-performance OpenGL shader-based rendering engine for very large data sets (1M+ atoms) on both Windows and Linux: Fall-back protocol to simpler models for low-end graphics hardware, including software rendering if necessary
• Provides a complete Python3 environment
  • Includes precompiled optimized libraries like numpy/scipy/ScaLAPACK (based on MKL), sympy, pandas, matplotlib/pylab, MPI4Py, SSL bindings, sklearn, pytorch, pymatgen, ASE, fireworks, Qt/PyQt, and many more
  • Supports pip for installation of additional Python modules, either in main installation or through virtual environments
• All output data stored in HDF5 files
• Add-on manager for installing plugins from Synopsys or third-party developers
• Floating license system

Python Scripting & Automatizations

A high-level interface based on Python underpins both the NanoLab GUI and all QuantumATK simulation input scripts. See the QuantumATK API Documentation for details on all classes and functions

• Scripts can be run in interactive mode (ipython) or in batch
• Built-in editor with Python code completion and syntax highlighting
• Use the Workflow Builder to create scripts for single calculations, or templates for automating batch jobs, with possibility to insert custom Python code blocks in workflows
• Interactive console in the Builder with direct access to the stash configurations
• Write addons and plugins in Python to add new functionality to the GUI such as new structure-building and analysis/plotting functionality, access to external databases, and support for additional remote job execution queue managers

Parallelization & Other Performance Options

• Compiled against Intel MPI and the Intel Math Kernel Library (MKL) to automatically provide an optimized balance between OpenMP threading and MPI
• Multilevel parallelism for complex workflows; for example, each NEB image can be run independently while each image is parallelized over k-points (using multiple processes per k-point if enough cores are available)
• Automatic threading intelligence to optimize efficiency when using hybrid MPI/OpenMP parallelization
• Use of "best in class" standard libraries/algorithms like ELPA, PETSc, SLEPc, ZMUMPS and FEAST, plus proprietary sparse matrix library
• PEXSI solver for O(N) calculations of very large systems (10,000+ atoms in DFT)
• Iterative diagonalization solver targeting a limited number of bands around the Fermi level; mostly beneficial for tight-binding where it allows for studies with 1M+ atoms
• Parallel memory distribution of e.g. the mixing history
• Caching of data for higher memory usage vs. faster performance, or opposite
• Options to use disk space instead of RAM to cache data like self-energies or Poisson grids
• GPU acceleration for certain force fields and MTP training, using CUDA

Learn more about QuantumATK

Test our software or contact us at [email protected] for more information.