QuantumATK

LCAO Total Energy Methods

  • Numerical atomic orbital basis sets with compact support
  • Optimized basis sets for most elements with low, medium and high accuracy
  • Norm-conserving Troullier-Martins pseudopotentials
    • FHI/SG15/PseudoDojo potentials provided for almost all elements of the periodic table, including semi-core potentials for many elements
    • PseudoDojo and SG15 potentials are fully relativistic
  • Around 400 LDA/GGA/MGGA exchange-correlation functionals via libXC
  • MetaGGA SCAN functional for significant improvements for energetics over GGA and LDA
  • Methods for accurate band gap calculations of semiconductors and insulators
    • MetaGGA (TB09)
    • DFT+1/2 method
    • Empirical "pseudopotential projector shift" method (parameters provided for Si and Ge)
  • Van der Waals models (DFT-D2 and DFT-D3)
  • Non-collinear, restricted and unrestricted (spin-polarized) calculations
  • Spin-orbit coupling
  • Hubbard U term in both LDA and GGA (also spin-dependent)
    • "Dual", "on-site", and "shell-wise" models
  • Counterpoise correction for basis set superposition errors (BSSE)
  • Ghost atoms (vacuum basis sets) for higher accuracy in the description of surfaces and vacancies
  • Virtual crystal approximation (VCA)
  • Analytical Force and Stress

PlaneWave Total Energy Methods

  • Plane-wave basis sets with default mesh cutoff setting for all elements
  • Hybrid functionals using the ACE algorithm
  • Norm-conserving Troullier-Martins pseudopotentials
    • FHI/SG15/PseudoDojo potentials provided for almost all elements of the periodic table, including semi-core potentials for many elements
    • PseudoDojo and SG15 potentials are fully relativistic
  • Projector-augmented wave (PAW) pseudopotentials (beta version)
    • Allows lower wave function cut-off than with normconserving PPs, for same accuracy
    • GPAW data set for LDA/GGA (default)
    • JTH data set for LDA/GGA (includes lanthanides)
  • Around 400 LDA/GGA/MGGA exchange-correlation functionals via libXC
  • MetaGGA SCAN functional for significant improvements for energetics over GGA and LDA
  • Methods for accurate band gap calculations of semiconductors and insulators
    • MetaGGA (TB09)
    • Hybrid functionals
    • Empirical "pseudopotential projector shift" method (parameters provided for Si and Ge)
  • Non-collinear, restricted and unrestricted (spin-polarized) calculations
  • Spin-orbit coupling
  • Eigensolvers
    • Default: Generalized Davidson method – stable and robust method
    • Also includes (as the first code) the Projected Preconditioned Conjugate Gradient (PPCG) algorithm for computing many extreme eigenpairs of a Hermitian matrix (cf. https://arxiv.org/abs/1407.7506 & https://doi.org/10.1016/j.jcp.2015.02.030); provides better scaling for large scale parallel calculations (single k-point, many processes per k-point)
  • Analytical Force and Stress

Semi Empirical Total Energy Methods

  • DFTB-type model, 30 different parameter sets are shipped with the product, and more can be downloaded and used directly
  • Built-in Slater-Koster models for group IV and III-V semiconductors (including strained models)
    • Interface for input of user-defined Slater-Koster parameters
  • Extended Hückel model with over 300 basis sets for (almost) every element in the periodic table
  • Tight-Binding models for strained systems (T. B. Boykin et al., Phys. Rev. B 81, 125202 (2010))
  • Spin polarization term can be added via internal database of spin-split parameters
  • Non-collinear spin
  • 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
  • Analytical Force and Stress

ForceField Total Energy Methods

  • Over 300  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 for etching and deposition simulations
  • BYOP (Bring Your Own Potential)
    • Python interface for adding your own or literature potential of any of the supported types
    • Support for custom combinations of potentials
      • E.g. use 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, Madden, and more
  • Coulomb solvers
    •  Ewald (smooth particle mesh), DSF, Debye, simple pairwise
  • Interface for adding your own or literature potential of any of the above types
  • Parallelized via OpenMP for optimal multicore performance
  • Parallelization over multiple MPI processes to speed up large-scale MD simulations
    • Works with Pair potentials, Stillinger-Weber, Tersoff, Coulomb potentials, Embedded Atom Model (EAM), all bonded FFs.

Ion Dynamics for LCAO, PlaneWave, Semi Empirical and ForceField

  • Quasi-Newton LBFGS and FIRE methods for geometry and unit cell optimization (forces and stress)
    • Simultaneous optimization of forces and stress
    • Optimize structure to specified target stress (hydrostatic or tensor)
    • Pre/post step hooks for custom on-the-fly analysis
  • Computation of dynamical matrix
    • Compute phonon band structure, DOS, and thermal transport
    • Compute and visualize phonon vibration modes
    • Compute the Seebeck coefficient, ZT, and other thermal transport properties by combining ionic and electronic results
    • Zero-point energy and free lattice energy can be obtained from the PhononDensityOfStates analysis object (vibrational free energy in quasi-harmonic approximation of molecules and bulk)
    • Wigner-Seitz approximation for large supercells
    • Uses crystal symmetries to reduce the number of displacements required
  • Geometry optimization of device structures (also under finite source–drain bias)
  • Calculation of transition states, reaction pathways, and energies
    • Nudged elastic bands (NEB) method, enhanced version developed in-house
    • Support for varying cell shape and size, to simulate e.g. phase changes
    • Climbing image method
    • Pre-optimized path using the image-dependent pair potential (IDPP) (http://scitation.aip.org/content/aip/journal/jcp/140/21/10.1063/1.4878664)
    • Parallelized over images
  • Molecular Dynamics (MD)
    • State-of-the-art MD dynamics methods
      • Runs with DFT, semi-empirical models, or classical potentials
      • All thermostats and barostats support linear heating and cooling
      • All barostats support isotropic and anisotropic pressure coupling and linear compression
    • Flexible constraints
      • Fix atoms
      • Separate X, Y, Z constraints
      • Fix center of mass in MD
      • Constrain Bravais lattice type (even when target stress is applied)
      • Fix space group (in geometry optimization)
    •  Thermostats and barostats
      • NPT with anisotropic stress
      • NVT Nosé-Hoover with chains
      • NVE Velocity Verlet
      • NVT/NPT Berendsen
      • Martyna-Tobias-Klein barostat
      • Langevin
    • Several options for initialization of velocities
    • Pre/post step hooks in Python for custom on-the-fly analysis or custom constraints, external forces, etc.
  • Flexible constraints
    • Fix atoms
    • Separate X, Y, Z constraints
    • Fix center of mass in MD
    • Constrain Bravais lattice type (even when target stress is applied)
    • Fix space group (in geometry optimization)
  • Partial charge analysis
  • Visualization of velocities
  • Interactive analysis tool for trajectory and single configuration properties (also for imported trajectories from LAMMPS, VASP, etc)
    • radial/angular distribution function
    • velocity autocorrelation
    • local mass density profile
    • coordination number
    • mean-square displacement
    • nearest neighbor number
    • neutron scattering factor
    • velocity/kinetic energy distribution
    • local structure analysis (Voronoi type)
    • centrosymmetry
    • vibrational density of states
    • The above analysis can be performed very efficiently for a selected subset of atoms, also in very large structures
  • Mechanical properties
    • Forces and stress (analytic Hellmann–Feynman)
    • Elastic constants
    • Local stress
  • Global optimization 
    • Genetic algorithm for crystal structure prediction
  • Time-stamped force-bias Monte Carlo
    • Alternative to molecular dynamics for long time-scale equilibration, deposition, amorphization, diffusion, sampling of rare events, etc., either at constant temperature of with a linear heating/cooling ramp
    • References: E.C. Neyts and A. Bogaerts, Theor. Chem. Acc. 132, 1320, 2012. M. J. Mees et al., Phys. Rev B 85, 134301, 2012.
  • 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
    • Two options: detailed analysis via phonon partition function, or quick estimate via curvature of NEB path
    • Metadynamics via the PLUMED library (http://www.plumed.org/)
  • Export movies of MD trajectories, phonon vibrations, NEB paths, etc.

Poisson Equation Solvers for LCAO, PlaneWave and Semi Empirical

  • FFT (for periodic systems)
  • Two solvers for systems including metallic/dielectric regions:
    • Multigrid
    • Conjugate gradient method (parallelized in memory and execution)
  • FFT2D solver for device configurations that have no metallic and dielectric regions.
  • "Direct" solver for large-scale calculations (parallelized in memory)
  • Multipole expansion for molecules
  • Dirchlet, von Neumann, or periodic boundary conditions can be specified independently in each direction
  • Metallic gate electrodes and dielectric screening regions
    • Allows for computation of transistor characteristics (gated structures) as well as charge stability diagrams of single-electron transistors

Performance Options for LCAO, PlaneWave and Semi Empirical

  • Consistent use of "best in class" standard libraries/algorithms like Intel MKL, ELPA, PETSc, SLEPc, ZMUMPS and FEAST
  • Proprietary sparse matrix library
  • Parallel memory distribution of e.g. the mixing history
  • Automatic adjustment of number of bands above the Fermi level to include
  • Multilevel parallelism
    • Over images in NEB and similarly for other complex tasks
    • Over k-points
    • Over basis functions (using multiple processes per k-point)
    • Also for band structure, DOS etc.
    • Automatic algorithm to determine the default (optimal) number of processes per k-point
  • Caching of data for higher memory usage vs. faster performance - or opposite
  • Use disk space instead of RAM to store grids for Poisson solver
  • PEXSI solver for O(N) calculations of very large systems (10,000+ atoms in DFT); cf. http://arxiv.org/abs/1405.0194
  •  Automatic threading intelligence
    • the number of threads is automatically controlled to make the best use of the available resources, taking into account the number of MPI processes used
  • Possible to combine MPI and openMP parallelization

Electronic Structure Analysis for LCAO, PlaneWave and Semi Empirical

  • Band structure
    • User defined Brillouin zone path through selection of high symmetry points
    • Fat bandstructure, shows projection onto atoms, spin, orbitals or angular momenta, in any desired combination
    • Effective bandstructure, i.e. unfolding of bandstructure for alloys and other supercells (no constraints on defect location, defect types, element)
    • Local bandstructure
  • Molecular spectrum
    • One-electron spectrum of molecules
    • Projected Gamma-point molecular spectrum for periodic systems
  • Density of states (DOS) 
    • Calculated using the tetrahedron method of gaussian smearing
    • Projection onto atoms, spin, orbitals or angular momenta, in any desired combination
    • Projections of band structure and DOS onto atoms, spin, orbitals or angular momenta, in any desired combination
  • Mulliken populations of atoms, bonds and orbitals 
  • Real-space 3D grid quantities as Python objects allowing for manipulations, evaluation at points,
    • Electron density
    • Partial electron density (simulate STM images within the Tersoff-Hamman approximation)
    • 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 
  • Total/free energy
    • Entropy contribution
  • Polarization and piezoelectric tensor
    • Calculated using the Berry phase approach
    • Calculation of Born effective changes
    • Optional internal ion relaxation
  • Effective mass analysis based on Finite Difference Method
  • Bader charges 
  • Born effective charges
  • Fermi surface
  • Optical properties 
    • Kubo-Greenwood formalism for linear optical properties
    • Calculation of optical adsorption, dielectric function, refractive index, etc.
  • Charge point defect study object
    • A framework for studying the properties of a defect in a host material, by setting up and running all the calculations required for a comprehensive study
    • Type of defects: vacancies, substitutionals, interstitials, pairs & larger clusters
    • Neutral and charged defects
    • Calculate relaxed defect structures, formation energies and trap levels
    • Can be used with all bulk calculators
    • Can specify different calculators for the relaxation and the calculation of formation energies and trap levels
    • Specify atomic chemical potentials or choose to have them calculated automatically
    • Ghost atoms enabled for vacancy sites, also during relaxation, for significantly better accuracy when using DFT-LCAO or Semi-empirical calculators
    • FNV correction scheme for charged defects with automatic Gaussian model charge fitting
    • Check convergence of defect properties with cell size and extrapolate to infinite size
    • Automatic adjustment of k-point sampling for different cell sizes to ensure best possible consistency between sizes
    • Elastic correction to account for the spurious residual stress caused by a defect centre in a finite supercell of the host material

Additional Electronic Structure Analysis for LCAO and Semi Empirical

  • Complex band structure
  • Bulk transmission spectrum
  • Heisenberg exchange analysis module
    • A novel method of computing exchange coupling constants for the Heisenberg model, using the Green's-function method
    • Works within the framework of density functional theory (DFT+U) combined with the LCAO basis set approach
    • The Heisenberg spin-lattice model is an empirical approach to study various magnetic properties at finite temperatures, e.g., to understand phase diagrams, phase transitions, and magnetization dynamics of the magnetic system
    • The main difference from the traditional approach, which is based on total energy calculations for multiple magnetic configurations, is that all the exchange coupling constants can be computed from a single magnetic configuration calculation
    • Easy to set up the HeisenbergExchange analysis such that only couplings between certain atoms are considered
  • Spin life time
    •  At technologically relevant temperatures (>100 K) the spin life time will be limited by electron-phonon interactions, mediated by spin-orbit coupling (Elliot-Yafet mechanism)
    • QuantumATK can calculate the phonon-limited spin life time from an ElectronPhononCoupling object (if computed with noncollinear spin and spin-orbit coupling)
  • Magnetic anisotropy energy (MAE)
    • Versatile study object for calculating the MAE using the force theorem
    • Works with LCAO and PlaneWave calculators
    • Calculate and plot MAE as a function of the chosen coordinate (X/Y/Z) at available theta and phi angles, site/shell/orbital-projected MAE

 

Special Features for LCAO, PlaneWave and Semi Empirical

  • Initialization of a new calculation via the self-consistent density matrix of a converged one (with automatic spin realignment)
  • Initialization of noncollinear spin calculations from collinear or spin-unpolarized ones for improved convergence
  • Custom initial spin-filling schemes
  • Odd/even k-point grids (Monkhorst-Pack or edge-to-edge zone filling), Gamma-centered or with custom shifts
  • Fractional hydrogen pseudopotentials and basis sets (for surface passivation)
  • Low-level interface to extract Green's function, Hamiltonian, overlap matrices, self-energies, etc.
  • Delta test module for benchmark of pseudopotential/basis set accuracy
  • Flexible and customizable verbosity framework to control the level of output to the log files
  • Region-dependent "c" parameter for TB09 Mega-GGA
  • Occupation functions: FermiDirac, Methfessel-Paxton, Gaussian, ColdSmearing
  • Local atomic shifts
  • Simulate external fields
  • Implicit solvent model
  • Support for charged systems
  • Compensation charges
    • Mimic charge doping
    • Passivate surface atoms 

NEGF for LCAO and Semi Empirical

  • NEGF method for two-probe systems
    • Non-equilibrium Green's function (NEGF) description of the electron distribution in the scattering region, with self-energy coupling to two semi-infinite leads (source/drain electrodes)
    • Open boundary conditions (Dirichlet/Dirichlet) 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
    • Use of electronic free energy instead of total energy, as appropriate for open systems
    • Ability to treat two-probe systems with different electrodes (enables studies of single interfaces like metal-semiconductor or p-n junctions, for instance)
    • Ability to add electrostatic gates for transistor characteristics
  • Surface Green's function 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 bandstructure – device density of states evaluated along a k-point route
  • 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
    • Options to store self-energies to disk, either during calculation (instead of RAM) or permanently, to reuse in other calculations
    • Multilevel parallelism up to 1000s of cores
    • Parallel device performance profile helps users decide what the best parallelization strategy is, and which Green’s function  methods  to use.
    • Adaptive (non-regular) k-point integration for transmission coefficients
    • Minimal Electrode Concept
      • Reduced electrode - automatically repeated for computing self-energies
      • Saves time in the electrode calculation which is O(N3)
  • Calculation of I-V curves
    • Elastic, coherent tunneling transport
    • IV Characteristics Study Object
      • Combined framework for running multiple source-drain/gate voltage calculations and collecting and analyzing the results
      • Multilevel parallelism
      • “Smart restart“
      • Custom settings for individual voltages
      • State persistence (via data in HDF5)
      • Custom drain-source voltages, plot current as function of gate source; current as function of drain-source for one or many gate voltages
      • Show on/off ratio, subthreshold slope, transconductance, DIBL, source-drain saturation voltage
    • Quasi-inelastic and fully inelastic electron-phonon scattering calculations, based on the lowest-order expansion (LOE) and extended LOE (XLOE) approximations, respectively
      • Works with any combination of methods for the electronic and ionic degrees of freedom (DFT, tight-binding, DFTB, classical potentials)
      • Many performance options, such as averaging over phonon modes (bunching), using energy-dependent relaxation energies, and repeating the density matrix for homogeneous systems
      • Inelastic transmission spectrum (IETS) analysis
    • Special thermal displacement (STD) approximation to efficiently capture the effect of phonon scattering on the I-V curve by creating a canonical average over all phonon modes. For more details, see arXiv:1706.09290
  • Photocurrent Module
    • New analysis module for calculating the photocurrent and photon-mediated transmission in a device using first-order perturbation theory within the 1st Born approximation
    • Also gives the total current based on illumination by the AM1.5 standard solar spectrum
  • Device Configuration Study Object for Relaxation of Devices
    • This study object fully automates the Bulk Rigid Relaxation (BRR) method, making it very simple to optimize the geometry of a device
    • Can relax also complex device systems
    • An option to restart calculations from partially optimized parts (auto-save every 15 mins)
  • Analysis of transport mechanisms
    • Transmission coefficients (k-point/energy resolved)
    • Monkhorst-Pack or edge-to-edge zone filling k-point scheme, or sample 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
    • Voltage drop
    • Molecular projected self-consistent Hamiltonian (MPSH) eigenvalues
    • Current density and transmission pathways
    • Spin-torque transfer (STT) for collinear/non-collinear spin
    • Atomic-scale band diagram analysis via LDOS or device DOS

Electron-Phonon interaction for LCAO and Semi Empirical

  • Extract electron-phonon coupling matrix elements
  • Compute deformation potentials and conductivity/mobility tensors from the Boltzmann equation, with constant, full k-point dependent and/or only energy-dependent relaxation times
  • Compute Seebeck coefficients and thermoelectric ZT (and underlying first moment and thermal conductance tensors)
  • Compute Hall coefficient and Hall conductivity tensors
  • Calculate phonon-limited momentum- and spin lifetimes.
  • Automated workflows for dynamical matrix (D) and Hamiltonian derivatives (dH/dR), possibly utilizing a Wigner-Seitz scheme for large systems
  • Tetrahedron integration method for calculating mobility and resistivity of nontrivial Fermi-surfaces or direct integrations for clever selections of BZ areas

NanoLab

  • Atomic geometry builder for molecules, crystals, nanostructures and devices
    • Symmetry information tool
    • Symmetrize crystal structures based on approximate space groups
    • Supercells
    • Interactive control of structure, select, edit, move, by atom, fragment, etc.
    • Surface cleaver 
      • Select Miller indices, surface Bravais Lattices and cleavage planes
      • Create slabs or supercell geometries 
    • Interface builder 
      • Analyze strain for different supercell sizes and crystal rotations
      • Optimize interface geometry
    • Icosahedron builder plugin
      • Build icosahedron nanoparticles
    • Wulff construction tool
      • Build nanoparticles with minimal surface energy
    • NEB tools
      • Set up path
      • Edit images collectively or individually
      • Pre-optimize NEB path with Image Dependent Pair Potentials (IDPP) 
      • Access interpolation algorithms  (LI-LinearInterpolation, HLC-HalgrenLipscomb, and IDDP-ImageDependentPairPotential) in Python scripts for easier automation of NEB path generation
    • Create device structures for transport calculations
    • Builders for nanostructures like graphene, nanotubes, nanowires
    • Molecular builder
    • Polycrystalline builder
    • Passivation tool for surfaces to remove bonds 
    • Import/export of most common atomic-scale modeling file formats (extendable by plugins; embedded version of OpenBabel)
    • Packmol plugin
    • Special Quasi-random Structures (SQS) algorithm for generating random alloys
      • Use a genetic algorithm (unlike other codes that perform an open-ended Monte Carlo simulation, which can be very slow)
      • Supports 2-component systems like SiGe or InGaAs
      • Any type of geometry, also nanowires etc.
    • Python Console
      • Provides direct Python access to interact with the configurations in the Builder
      • Maps (some) operations in the Builder to Python commands
      • Create pre-defined scripts (”snippets”) to automate repeated tasks
  • Databases
    • Internal structure library with several hundred basic molecules and crystal structures
    • Interface to query online databases such as
      • Crystallography Online Database (http://www.crystallography.net/cod/)
      • Materials Project
    • Support for custom, internal databases based on MongoDB or MySQL
  • Easy setup of calculations, even advanced work-flows
    • Full range of functionality for LCAO, PlaneWave, SemiEmpirical and FordeField
    • Edit input files (python scripts) using the NanoLab editor
    • Save your calculator settings and workflows as templates and reuse them in future calculations
  • Viewer for 3D data
    • High-performance shader-based rendering engine for very large data sets (1M+ atoms and bonds)
    • Isosurfaces, isolines, and contour plots, with graphical repetition with data range control
    • Control atom color, size, transparency, etc.
    • Color atoms by computed quantities, like forces, velocities
    • Also works in movies, e.g. MD trajectories
    • Polyhedral rendering of crystals
    • Voxel plot (point cloud) rendering of 3D grids
    • Vector field plots
    • 3D extrusion of contour plans
    • 3D scene control, multiple light sources
    • Brillouin zone explorer
    • 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
  • 2D plot framework
    • Perform advanced editing of plots, such as changing color, line, width, etc. of multiple items (several bands for instance) at once, changing title axes, legend, etc., editing grid layout, and adding annotations like arrows and labels
    • Save customized plots for further analysis and reuse plot setups with new data
    • Link and combine plots, e.g. band structure and DOS, for more insightful analysis
    • Fit data to linear and other models and measure directly in graphs
  • Project management
    • Organize data files into projects
    • Easily transfer projects between computers, or share with other users
    • Overview all data in a project, or focus on particular subsets, then combine data sets from different files for advanced analysis
  • Editor
    • Search-and-replace
    • Syntax highlighting
    • Python code completion
    • Select font
  • Job Manager
    • Submit and run jobs from the GUI in serial, using threading, and in parallel using MPI, or OPENMPI and MPI together
    • Submit jobs from the GUI to local machines
    • Submit jobs from the GUI to remote machines
      • A variety of queue types: Torque/PBS, LSF, SLURM, SGE, and direct execution (no queue)
      • Additional queue types can be added by plugins
      • Requires only SSH access from client to server (no server-side daemon is required, all is controlled by the client)
      • Automatically copies input and output files to/from remote resources
      • Built-in SHH key generation and transfer to remote host (no need of 3rd party programs)
      • Diagnostics tool checks that added machine settings are correct
  • Python scripting interface, directly coupled to GUI
    • Can also be used interactively
    • Parallel scheduler
    • Includes PyQt54
    • PyMatGen included (pre-compiled)

Python Scripting and Automatization

Python Scripting is the component that binds all the calculators together in a common interface and allows them to synergistically work together. It also enables users to automate and customize tasks (also in NanoLab). 

atkpython is a python 3.6. interpreter with a large number of python modules preconfigured. It can run in interactive mode and in batch mode. The input format for QuantumATK is a python script which setup the simulation using native python commands together with QuantumATK python functions for

  •  Structure generation
    • Define molecule, bulk, surface and device geometries
    • Define Bravais lattices
    • Build special geometries like nanowires, graphene sheets, nanotubes
    • Reproduce workflows from the NanoLab builder using builder python commands
  • Simulation Setup 
    • Define simulation setup for QuantumATK DFT-LCAO, DFT-PlaneWave, TightBinding or ForceField
    • Define workflows which combine simulation engines
    • Add post or pre-hooks to Molecular Dynamics simulations, thereby tailoring the MD simulation algorithm
  • Post Analysis 
    • Automate analysis and plotting
    • Access internal QuantumATK variables for specialized analyses
    • Batch processing of analyses
    • Combined analysis of different simulations
  • There are more than 400 QuantumATK classes and functions available to the user, see list here
  • Variables are defined with physical units and QuantumATK allows for conversion between different units
    Units: nm, Ang, Bohr, Meter, Rydberg, eV, meV, Hartree, Joule, Calorie, kiloCaloriePerMol, kiloJoulePerMol, Newton, nanoNewton, kilogram, Kelvin, fs, femtoSecond, picoSecond, nanoSecond, microSecond, millisecond, Second, Minute, Hour, Day, Ampere, Volt, Siemens, G0, Coulomb, bar, Pa, Gpa, hbar, Mol, Radians, Degrees
  • Physical Constants    
     boltzmann_constant, planck_constant, Avogadro_number, speed_of_light, atomic_mass_unit, hbar, electron_mass, elementary_charge, vacuum_permitivity
  • 3rd party Python modules available from atkpython    
     ADODBAPI, ASE, CCLIB, Certifi, Colorama, Crypto, Decorator, H5py, Ipykernel, Ipython, Isapi, Jinja, Jupyter_core, markupsafe, matplotlib, monotonic,  monti, mpi4py, networkx, numpy, packaging, paramiko, pexpect, pickleshare, pillow, pkgconfig, plumed, psutil, pupynere, pybtex, pycrypto, pygments, pymatgen, pymongo, pymysql, PyOpenGL, PyQt5, pythonwin, pytz, pywin32, pyyaml, pyzmq, qtconsole, requests, scandir, scipy, simplegeneric, singledispatch, sip, six, spglib,  tornado, tabulate, traitlets, wcwidth, win_unicode_console, win32, win32com, zmq

Platform Support

  • QuantumATK P-2019.03 is based on Python 3.6
  • Self-contained binary installer - no compilation needed, no external library dependencies beyond standard operating system packages
    • Support for all modern 64-bit Windows and Linux versions (detailed system requirements)
    • Provides a complete Python environment with precompiled optimized libraries like numpy/scipy/ScaLAPACK (based on MKL), matplotlib/pylab, Py4MPI, SSL bindings, Qt/PyQt, etc.
  • Parallelization (Windows/Linux)
    • QuantumATK is compiled against Intel MPI and the Intel Math Kernel Library (MKL) which in combination automatically provide an optimized balance between OpenMP threading and MPI
    • Intel MPI is included in the shipment
    • Support for MPICH2/MPICH3 (Ethernet), MVAPICH2 (Infiniband), and other MPICH-compatible libraries
  • Floating license system (SCL from Synopsys)