A new Python code, dbaAutomator, is now available to help BerkeleyGW users working on molecular crystals verify the convergence of the fine k-point grid and perform double-Bader analysis (DBA) of exciton character. A full account is provided in Journal of Physics: Condensed Matter, https://doi.org/10.1088/1361-648X/ab699e. Briefly, to check the fine grid convergence, dbaAutomator applies a criterion based on requiring that the exciton wave-function should be mostly contained in the central region of the super-cell. To streamline the performance of DBA, the code determines the hole positions to sample, generates input files for BerkeleyGW calculations, and computes the degree of charge transfer character for the resulting exciton wave-functions. The dbaAutomator code is distributed under an open-source GPL license. The code and documentation can be downloaded from the URL: https://github.com/BLABABA/dbaAutomator.
We are releasing today a new version of BerkeleyGW. BerkeleyGW 2.1 is the first version based on a new and more modern coding infrastructure, with better support for new compilers and improved consistency checks. For the end users, the main noticeable features include increased performance and bug fixes for I/O operations involving the new HDF5 file format and for the subspace code. We also improved considerably the documentation of the code, with a new and expanded user manual.
Some highlights and features for the end user:
- New user manual for the code, which comes bundled with the code, and which is
also available online: http://manual.berkeleygw.org
- New wrapper for the StochasticGW code.
- Bug fixes when writing HDF5 wavefunctions in parallel which could cause the code to hang (relevant to the ParaBands code)
- Improved error checking for operations involving HDF5 files.
- Improved support for compilers, including PGI and NAG.
- Improved performance and stability for building BerkeleyGW in parallel with new dependency system.
- Improved performance of HDF5 routines for the subspace code and for reading chimat.h5 files.
There will be an advanced track and the possibility of contributed presentations and posters from returning BerkeleyGW users. After the workshop, there will be a two-day scientific meeting on 6-7 June (details to be announced soon).
We are releasing today the next major version of BerkeleyGW. BerkeleyGW 2.0 represents the culmination of nearly two years of development effort, and this release contains a number of important new features and capabilities including:
1. The initial release of ParaBands: a new tool for efficiently generating wave-function files including many empty orbitals required for BerkeleyGW calculations.
2. Full BSE calculations that do not employ the Tamm-Dancoff approximation.
3. Improved algorithms for k-point sampling in 2D, which include the newly proposed nonuniform neck subsampling (NNS) and the cluster sampling interpolation (CSI) algorithms.
4. Accelerated full-frequency GW calculations through the use of a low-rank subspace approximation for expressing the dielectric matrix. In fact, large-scale full-frequency GW calculations are now faster than calculations using plasmon-pole models!
5. Significant performance improvements throughout, but particularly in the calculation of the full-frequency dielectric matrix and evaluation of the full-frequency Sigma operator. Continued optimizations were made throughout the package for multi- and many-core architectures including Intel Xeon-Phi, which allows BerkeleyGW to scale half a million cores on Cori 2 for large-scale calculations!
6. Improved user and developer documentation, as well as a new quick reference guide (see the link on the top of the page).
We hope you enjoy this release, and let us know through the help forum if you encounter any problem!
– BerkeleyGW development team
We have a mailing list for users to request help building and using BerkeleyGW as well as a forum for developers. You may send an email to the list without joining or may request to join the list to participate in the community.
User Help Forum: https://groups.google.com/a/berkeleygw.org/forum/#!forum/help
Developer Mailing List: https://groups.google.com/a/berkeleygw.org/forum/#!forum/developers