BGW WFN IO

A pure C library to read and write wavefunction files in HDF5 format according to the BerkeleyGW format specification.

Instructions

You should build the code using either CMake or by adjusting the provided Makefile template.

Using CMake

Follow these steps:

mkdir build && cd build
cmake ../
make
make test

You may need to manually specify the compiler with the CC flag, e.g., CC=mpicc cmake ../.

Manually editting the sample Makefile

Manually edit the Makefile and make the project. A library libbgw_wfn_io.so will be created.

Testing

1. Run ./test_bindings.x to test the library. It will read the input file WFN_in.h5 and write the output file WFN_out.h5.
2. You can check the correctness of the program with h5diff -v -c WFN_in.h5 WFN_out.h5 /

TODO

• Improve CMake support.
• Improve documentation.
• Implement parallel I/O for wavefunction coefficients (check distrib. w/ Alfredo).
• Add optional flag in the WFN file when the wavefunction is stored in the full FFT grid. Can optimize BGW for that case (e.g., Umklapp vectors -> cycle shift).

Developers

• Used CMake structure from: https://gitlab.com/CLIUtils/modern-cmake/-/tree/master/examples/extended-project.