ESPResSo > About > Features

Features

Characteristics

ESPResSo can perform Molecular Dynamics simulations of bead-spring models in various ensembles ((N,V,E), (N,V,T), and (N,p,T)). It is optimized for coarse-grained models and has the following characteristics:

  • ESPResSo is controlled by a scripting language (currently Tcl, soon: Python), which gives it its gerate flexibility
  • ESPResSo is extensible, which allows users to add new methods and algorithms
  • ESPResSo is open-source and free (License: GPL (GNU General Public License)
  • ESPResSo is parallelized, i.e. it can run on many processors in parallel
  • ESPResSo is portable, i.e. it runs on a wide variety of hardware platforms, like desktop workstations, convenience clusters as well as high performance supercomputers based on POSIX operating systems (e.g. Unix or Linux)

Methods and Algorithms

ESPResSo contains  a number of advanced algorithms for coarse-grained simulations:

  • Statistical ensembles: NVE, NVT, NPT,  μVT
  • Nonbonded potentials: Lennard Jones, Buckingham, Morse, Generic tabulated potentials, etc.
  • Bonded potentials: harmonic spring, FENE, generic tabulated bonded potentials, etc.
  • Anisotropic interactions: e.g. Gay-Berne particles or other non-isotropic interactions
  • Advanced methods for electro- and magnetostatics: e.g. P3M, MMM1D, MMM2D, ELC, dipolar P3M, MEMD
  • Constraints: all or some of the  coordinates of particles can be fixed, various spatial constraints (walls, spheres, pores, …) can interact with the particles
  • Rigid bodies: arbitrary extended objects can be constructed from several particles
  • Dynamic bonding: when particles collide, new bonds can be generated between them to study agglomeration
  • Hydrodynamics: Lattice-Boltzmann fluid (optionally on a GPGPU), DPD (Dissipative Particle Dynamics)
  • Analysis: numerous analysis functions exist, visualization with e.g. VMD or paraview

What ESPResSo is not

  • ESPResSo is not Quantum Espresso, which is an integrated suite of computer codes for electronic-structure calculations and materials modeling on the nanoscale.
  • ESPResSo is not a simulation program for all-atom simulations as they are used e.g. for protein simulations! There are many other programs which are more suitable for this kind of simulation, for example GROMACS, NAMD or GROMOS.