The Chroma Library for Lattice Field Theory

The Chroma package supports data-parallel programming constructs for lattice field theory and in particular lattice QCD. It uses the SciDAC QDP++ data-parallel programming (in C++) that presents a single high-level code image to the user, but can generate highly optimized code for many architectural systems including single node workstations, multi and many-core nodes, clusters of nodes via QMP, and classic vector computers.

Code releases:

Source Code

Chroma source code is available via github. You can also see the the Git FAQ for instructions on downloading the code. Currently the following branches are availble:

• The master is the canonical stable branch
• The devel branch is the branch with the proposed changes for the next version

Chroma releases are available as release tags on GitHub.

Building Chroma

The following tools help build and install Chroma and its dependencies:

• Chromaform automates downloading, building, and installing Chroma and QDP, with options for CPU builds and GPU builds using CUDA or HIP. See the repository for build options and examples.
• The package repository provides scripts for building Chroma with QDP-JIT, the GPU implementation of QDP++, and their dependencies. Choose the build configuration for your target system from the repository.

For QDP documentation and source code, visit the QDP++ project page, the QDP++ source repository, and the QDP-JIT source repository. Chroma also supports building with CMake.

Support codes

There is source code available via github that support file manipulations of chroma output files.

Dependencies

In order to build Chroma you'll need to have installed

• QDP++ and its dependencies. You may need the following tarballs:
  • QDP++ itself: The current recommended version is 1.44.0
  • Libxml2: If you don't have this, you can use this copy of the source. On Linux and Cygwin Systems there is a package for libxml2. On RedHat systems it is called "libxml2-devel".
  • QMP Message Passing for parallel builds: The current version of the source for QMP is here.
• For RHMC coefficients you will need GNU Multiple Precision Arithmetic Library (GMP).
• GPU: You need to download and install QUDA: A Wilson/Clover inverter package for CUDA based GPU devices. Then point out its existence to chroma with a --with-quda=<quda-install-dir> configure option. Remember to check the QUDA web page and/or the acknowledgement info to cite the authors appropriately

Relevant source code links:

• QDP++ - SciDAC C++ data-parallel programming interface
• QMP - SciDAC message passing programming interface
• USQCD Software - home page for software distributions

User Information

Links to tutorials are on the side-bar. There is also a collection of notes in the source distribution.

Acknowledging Chroma

If you use Chroma in your research, please cite:

R. G. Edwards (LHPC Collaboration), B. Joó (UKQCD Collaboration), "The Chroma Software System for Lattice QCD", arXiv:hep-lat/0409003, Proceedings of the 22nd International Symposium for Lattice Field Theory (Lattice2004), Nucl. Phys B1 40 (Proc. Suppl) p832, 2005. doi:10.1016/j.nuclphysbps.2004.11.254.

Chroma usage

Fun graphic showing locations of some of the Chroma users that we could find. Hover over the points to see the locations. Please let us know of more such sites.