Installation

For general information on installing the module and downloading the example notebooks, please refer to the HQStage documentation.

Please note that HQS Molecules is currently only supported on Linux.

Parts of this module require three third-party software packages that are not available for installation via pip: Open Babel, xTB and CREST.

1. Installation of Open Babel:
   For the user to benefit from the full scope of the 2D-to-3D structure conversion functionality, we recommend installing Open Babel. Open Babel can be installed via the package managers of various Linux distributions (e.g., apt on Debian 12) or alternatively from the conda-forge channel. Note: The 2D-to-3D structure conversion functionality uses the Open Babel package as a fallback option if the structure conversion of a molecule via RDKit fails. It is still possible to use HQS Molecules without Open Babel. In that case, the functionality will only be able to use RDKit for structure conversion.

2. Installation of xTB: To make use of the interface to the xTB program for semiempirical calculations, the xtb binary must be provided by the user in the PATH variable. We strongly recommend to download the binary release 6.7.1 from GitHub, since Hessian calculations with the GFN-FF method are known to fail with version 6.7.0. Besides that, an installation from conda-forge is possible, in principle, but it is known to fail for specific calculations (like e.g. Hessian calculations for linear molecules).

3. Installation of CREST: To make use of the interface to the CREST program for conformer search, the crest binary must be provided by the user in the PATH variable. We recommend downloading the binary release 3.0.2 from GitHub.