pysimm is an open-source object-oriented Python package for molecular simulations. It handles data organization for particles, force field parameters, and simulation settings so you can focus on developing your simulation workflow. Create long linear polymer chains structures modeled with common atomistic force fields.

  • LAMMPS Integration

  • Cassandra Integration

  • Support for Common Atomistic Force Fields

  • Integration with dedicated software for geometry analysis


This software package performs quantum nonadiabatic molecular dynamics simulations in the full multiple spawning and full multiple cloning approximations.  It is written in Python, highly extensible, and designed to take advantage of large-scale shared computer resources.


MCCCS-MN is a free, open-source Monte Carlo software tailored for simulations of phase and adsorption equilibria in the Gibbs ensemble using the TraPPE force field. MCCCS-MN is particularly efficient for equilibria involving multiple condensed phases and articulated molecules. MCCCS–MN uses hybrid MPI/OpenMP for parallel execution, has been adapted to processors with high-bandwidth MCDRAM, and workflows with specific I/O handling allow for capacity jobs at DOE Leadership Computing Facilities.


Sella is a Python 3.5+ software package which can be used to rapidly and reliably refine first order saddle points on molecular potential energy surfaces for the purpose of rate constant calculation in conventional transition state theory.

Sella is not globally installed on any supercomputer systems, but it has been tested on NERSC Cori and ALCF Theta.

EMSL Arrows

EMSL Arrows is a revolutionary approach to materials and chemical simulations that uses NWChem and chemical computational databases to make materials and chemical modeling accessible via a broad spectrum of digital communications including posts to web APIs, social networks, and traditional email.


KinBot 2.0 is a complex workflow software written in Python that carries out many of the tasks that enables the automatic calculation of pressure- and temperature-dependent rate coefficients for multiwell systems. KinBot communicates with third-party quantum chemistry packages via the Atomic Simulation Environment (ASE, interface to have maximum flexibility.

ECC is currently adding reaction families that happen on catalytic solid surfaces and integrating Sella into the workflow.


NWChem aims to provide its users with computational chemistry tools that are scalable both in their ability to treat large scientific computational chemistry problems efficiently, and in their use of available parallel computing resources from high-performance parallel supercomputers to conventional workstation clusters.

NWChem software can handle:

Reaction Mechanism Generator (RMG)

Reaction Mechanism Generator (RMG) is an automatic chemical reaction mechanism generator that constructs kinetic models composed of elementary chemical reaction steps using a general understanding of how molecules react. The aspects related to Heterogeneous Catalysis (until recently developed on a fork known as RMG-Cat) are supported by this award. RMG-Py is written in Python, with many parts using Cython for speed, and several external dependencies.


RASPA is a software package for simulating adsorption and diffusion of molecules in flexible nanoporous materials. The code implements the latest state-of-the-art algorithms for molecular dynamics and Monte Carlo in various ensembles. Applications of RASPA include computing coexistence properties, adsorption isotherms for single and multiple components, self- and collective diffusivities, and visualization. RASPA is particularly efficient for gas adsorption in a wide variety of porous materials.

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