ELSI - ELectronic Structure Infrastructure¶
ELSI provides and enhances scalable, open-source software library solutions for electronic structure calculations in materials science, condensed matter physics, chemistry, molecular biochemistry, and many other fields. ELSI focuses on methods that solve or circumvent eigenvalue problems in electronic structure theory. The ELSI infrastructure should also be useful for other challenging eigenvalue problems.
Purpose of Module¶
ELSI deals with the Kohn–Sham eigenvalue problem, which is central to Kohn–Sham density-functional theory, one of the most widely used methods in electronic structure. This problem is often the bottleneck in large scale calculations by high-performance computation and many different algorithms and strategies exist to tackle it. ELSI acts as a unified software interface to access different algorithms and their corresponding implementations. This greatly simplifies the implementation and optimal use of the different strategies.
One of the key design pillars of ELSI is portability and support for various computing environments, from laptop-type computers all the way to the most efficient massively parallel supercomputers and new architectures (GPU and manycore processors).
The libraries currently supported in ELSI are:
- ELPA (massively parallel dense eigensolvers)
- libOMM (orbital minimization method)
- PEXSI (pole expansion and selected inversion)
- EigenExa (massively parallel dense eigensolvers)
- SLEPc-SIPs (sparse eigensolver based on shift-and-invert spectral transformations)
- NTPoly (density matrix purification)
ELSI is used in several electronic structure codes, such as DFTB+, DGDFT, FHI-aims, and SIESTA.
Building and Testing¶
ELSI can be installed as part of the ESL-Bundle. Instructions to build the ESL-Bundle are provided in the ESL Bundle module.
ELSI can also be built with EasyBuild by using the ESL Easyconfigs module.
Detailed instructions on how to build ELSI without using the above options are provided in the User Manual. ELSI uses the CMake build system and the procedure to build it is fairly standard:
mkdir build
cd build
cmake [options] /path/to/elsi/sources
make
make install
A complete list of options can be found in the User Manual.
ELSI also provides several test programs. To run the test programs one first needs to enable them when running CMake with the following option:
-DENABLE_TESTS=ON
The test programs can be launched with
make test
Source Code¶
The ELSI source code is available from the ELSI website or from the ELSI Gitlab server.
ELSI was added to the ESL Bundle in the following Merge Request: