The bqb File Format

bqb Format

This is the homepage of the bqb file format. It enables lossless compression of simulation trajectories. For more details, please see our recent article:

M. Brehm, M. Thomas: "An Efficient Lossless Compression Algorithm for Trajectories of Atom Positions and Volumetric Data",  J. Chem. Inf. Model. 2018, 58 (10), 2092–2107, DOI 10.1021/acs.jcim.8b00501


The bqbtool is a command-line utility for working with the BQB file format. It enables to compress and decompress trajectories. The bqbtool is written in C++, contains around 41 000 lines of source code, and is distributed as free software under the GNU LGPL v3 license. It does not require any external library and is platform independent. Make sure to check the manual before trying it out.

Revision History:

May 04 2020 Fixed some bugs, including one which affected the compression ratio when compressing position trajectories.
Jan 01 2019 Fixed a (seldomly occurring) bug with handling BQB file index frames.
Oct 01 2018 Initial release of bqbtool.

Please download:

FileType / SizeLast Changed
bqbtool source code .tar.gz, 890 kiB May 04 2020
bqbtool Windows executable (64 bit, preferred version) .zip, 1.1 MiB May 04 2020
bqbtool Windows executable (32 bit, compatibility version) .zip, 1.1 MiB May 04 2020
bqbtool manual .pdf, 763 kiB Oct 01 2018

There is also a new TRAVIS release out which offers the full functionality of the bqbtool. Simply use the TRAVIS executable as if it was the bqbtool. Apart from that, TRAVIS can now directly read and analyze compressed BQB trajectories.

Please also see our new tutorial on vibrational spectroscopy.


We are also planning to publish a C++ library ("libbqb") which can be used to equip any software package with support for reading and writing compressed bqb files. Then, simulation programs such as CP2k or LAMMPS might directly write compressed trajectories, while visualization programs such as VMD could directly read the compressed files without prior decompression. It will take a few more months until the libbqb is ready for its first public release. Please stay tuned.

Quick Links:

TRAVIS ORCA MD Spectroscopy bqb Format