Proprietary Software

Advancing Discovery Science and Innovation

LLNL’s large-scale codes incorporate multiform physics and engineering to model and simulate incredibly complex systems that would be too expensive, impractical, or impossible to physically demonstrate.


ALE3D is a 2D and 3D multi-physics numerical simulation software tool using arbitrary Lagrangian-Eulerian (ALE) techniques used not only by LLNL staff, but by other programs across the nuclear security enterprise and Department of Defense.

The code uses finite element and finite volume formulation to model fluid and elastic-plastic response on an unstructured grid.

Additional ALE3D features include heat conduction, chemical kinetics and species diffusion, incompressible flow, wide range of material models, chemistry models, multi-phase flow, and magneto-hydrodynamics for long (implicit) to short (explicit) time-scale applications.


ALE3D4I, is a special version of ALE3D and is available for U.S. companies and academics. More information on licensing can be found here.

ALE3D INTRODUCTORY CLASS via Microsoft Teams – Jan. 23 thru Jan. 27, 2023 – (Registration not open, cost $1000)
This introductory class covers the basics of running the code and describe some of the theory behind its various physics modules. There is a mix of lecture and hands-on training during the five days. The target audience are those who have performed some computational modeling. Some experience running ALE3D is helpful, but not required. Users must have a valid, current license. LLNL employees must have a valid LC account and group ale3d_au.

ALE3D ADVANCED CLASS via Microsoft Teams – Spring 2023 – (Registration not yet open)
This is an advanced class in the use of ALE3D. While many of the topics presented here are presented in the introductory course, this class will cover these topics in much greater detail. The target audience are those who are users of ALE3D, and previous attendance of the introductory ALE3D course is highly encouraged.

Users who are licensed and on the waitlist will be given priority once registration opens. If you wish to be put on the waitlist, please email ale3d-help [at] llnl.govclass="spamspan" data-auth="NotApplicable" target="_blank". Registration will be on a per-submodule basis so attendees can sign up for one or all of the submodules at the time of registration.

ALE3D is a limited access code. No foreign nationals please.
Contact ale3d-help [at] llnl.govclass="spamspan" to find out if you are qualified to attend and to be sent an invite as soon as the registration website opens.

Visual result of ALE3D simulation


Download a complete list of ALE3D presentations and papers here.


For questions regarding ALE3D, please email: ale3d-help [at]


Cheetah, an LLNL thermochemical computer code, is a convenient and accurate physics- and chemistry-based computational tool for predicting the detonation velocities and energy release properties of energetic materials such as explosives, propellants, and pyrotechnics.

Cheetah employs advanced concepts and theories of fluids and solids at high pressures and temperatures to model the thermodynamics of explosion products that result from the detonation of modern condensed, energy-dense explosives. The results can be used for materials design, performance predictions and formulation optimization, as well as safety analyses, accident forensics, and even to study homemade and terrorist devices. WCI makes particular use of the Cheetah database, which currently includes a wide range of approximately 1,000 chemical ingredients and products.

The science base of the Cheetah code is being updated continually to incorporate new theoretical and experimental results relevant for the physics and chemistry of high-pressure and temperature phenomena.

For more information on updates, visit here.

Cheetah simulation code image


Cheetah is not a publicly available code and can only be used by active LLNL employees and our partners in the Department of Defense.


For questions regarding Cheetah, please email: sbastea [at]


HYDRA is a 2D and 3D multi-physics code used to design and simulate Inertial Confinement Fusion (ICF) and High Energy Density (HED) targets. It is a Lagrangian-Eulerian code based upon a multiblock mesh.

HYDRA has a broad range of physics models useful for simulating indirect drive, direct drive, and magnetic drive targets. These include 3D models for laser ray trace, electron transport, magneto hydrodynamics (MHD) with full Ohm’s law, ion beam transport, radiation transport, thermonuclear burn and burn product transport. HYDRA has a range of capabilities for modelling atomic physics, including inline non-local thermal equilibrium (NLTE) kinetics.


HYDRA can be made available to collaborators in ICF research on specific DOE computers.

HYDRA simulation code image


For questions regarding HYDRA, please email: marinak1 [at]


ParaDyn is a parallel implementation of the DYNA3D engineering simulation code designed to run on distributed memory, message-passing parallel computers. These programs include many Lagrangian finite element functionalities: hexahedral and structural element types, smooth particle hydrodynamics (SPH), over seventy material models, some using related equations of state, and sophisticated contact interface algorithms.

ParaDyn models a range of nonlinear material behavior including elasticity, plasticity, composites, some thermal effects, failure, and rigid body motion. Contact interfaces include frictional behavior, arbitrary interface motion, and material failure transitioning to free particles. So-called "mesh-less" techniques for particle-based spatial discretization remain an area of active R&D.

ParaDyn simulation code image


ParaDyn can only be used by LLNL employees and by our collaborators in the Department of Defense.


For questions regarding ParaDyn, please email: giffin1 [at]

Collaboration Fuels our Innovation

LLNL developers create and evolve software daily.

While some of this software can only be used internally, LLNL still maintains a vast portfolio of open-source projects that includes applications, libraries, compilers, and other tools that can be accessed by GitHub for public use and collaboration.

Use Open-Source Software

Building the Next Generation of Codes

The next generation of supercomputing will require significant development of simulation codes, code architectures, and applications development in order to provide leading edge simulations capabilities. 

Open and exciting opportunities include: 

  • Advancing AI, data analytics, machine learning, predictive modeling, statistics, UQ, and more
  • Maximizing the efficiency of software development and deployment
  • Innovating in new directions for next-generation hardware designs and platform
  • Deploying operation integrations in one of the world’s largest HPC data centers  

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physicist standing in front of a large screen of a code simulation