MBX
===

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      **A data-driven many-body energy and force engine for molecular simulations.**
      MBX powers classical, quantum, and path-integral MD using MB-pol and MB-nrg
      many-body potential energy functions (PEFs).

      .. button-link:: https://github.com/paesanilab/MBX
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         GitHub Repo

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.. _mbx-what:

What is MBX?
------------

MBX is a **C++ library** that provides energies and forces for data-driven  
**many-body potential energy functions (PEFs)**, including:

- **MB-pol** for water  
- **MB-nrg** for halide and alkali-metal ions  
- CO₂, CH₄, NH₃ and mixed gas-phase / condensed-phase systems  
- Covalently bonded molecules (e.g., alkanes, N-methyl acetamide)

MBX interfaces with molecular-dynamics engines such as:

- **LAMMPS** (recommended for classical MD due to performance)  
- **i-PI** (recommended for path-integral MD)  

MBX acts as a client that returns energies and forces, while the MD engine
controls the trajectory.  

The library supports:

- OpenMP and MPI parallelism  
- Classical, quantum, and hybrid MD  
- Periodic & nonperiodic simulations  
- JSON-based configuration  
- Many-body expansions via the MB-nrg formalism  

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Learn about it
--------------

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.. admonition:: External site 
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   Official site: `MBX <https://mbxsimulations.com/>`_

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.. _mbx-tutorials:

Tutorials
---------

The MBX tutorials include:

- Compilation and installation  
- Testing and benchmark workflows  
- JSON configuration  
- Stand-alone executables  
- LAMMPS and i-PI interfaces  
- Using MB-nrg / MB-pol with external force fields  

.. button-link:: https://mbxsimulations.com/tutorials
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   Online Tutorials

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.. _mbx-updates:

Updates
-------

Recent versions:

- **MBX v1.3.0** — 2025-07-09  
- **MBX v1.2.0** — 2024-08-20  
- **MBX v1.1.0** — 2024-04-22  

All performance improvements and new MB-nrg PEFs are listed on the `Updates <https://mbxsimulations.com/updates>`_ page.

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.. _mbx-team:

Team & Contributors
-------------------

MBX is developed and maintained by:

- **Paesani Research Group**, UC San Diego  
- Current contributors include:  
  Xuanyu Zhu, Richa Rashmi, Henry Agnew, Ethan Bull-Vulpe, Xinmao Lyu,
  Ruihan Zhou, Yuehua Xie, Shishir Iyer `(see About Us page) <https://mbxsimulations.com/about>`_ 

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.. _mbx-faq:

FAQ
---

MBX is continuously updated with new PEFs and performance improvements.

For questions about:

- Installation  
- LAMMPS / i-PI interfaces  
- Runtime errors  
- Slow performance diagnostics  

Users should consult the `FAQ <https://mbxsimulations.com/faq>`_ or post on the `MBX Google Group <https://groups.google.com/g/mbx-users>`_.  

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.. _mbx-download:

Download
--------

The latest version of MBX can be downloaded from GitHub:

.. button-link:: https://github.com/paesanilab/MBX/archive/refs/tags/v1.3.0.zip
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   MBX GitHub Releases

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.. _mbx-publications:

Key Publications
----------------

**MBX v1.2: Accelerating data-driven many-body MD simulations.**  
S. Gupta, E. F. Bull-Vulpe, H. Agnew, S. Iyer, X. Zhu, R. Zhou,  
C. Knight, F. Paesani, *J. Chem. Theory Comput.* **21**, 1838 (2025).  
`https://doi.org/10.1021/acs.jctc.4c01333 <https://doi.org/10.1021/acs.jctc.4c01333>`_

**MBX: A many-body energy and force calculator for data-driven many-body simulations.**  
M. Riera, C. Knight, E. F. Bull-Vulpe, X. Zhu, H. Agnew, D. G. A. Smith,  
A. C. Simmonett, F. Paesani, *J. Chem. Phys.* **159**, 054802 (2023).  
`https://doi.org/10.1063/5.0156036 <https://doi.org/10.1063/5.0156036>`_