Introduction

The HQS NMR Tool is the first package in the HQStage module HQS Spectrum Tools. With the HQS NMR Tool you can calculate and analyze NMR spectra for molecules or other spin systems. The tool is a Python-based library with a python API and uses RUST and C++ components for performance critical calculations.

Our NMR spectrum solvers are designed for both speed and precision. They are based on a very efficient implementation in the frequency domain. With a variety of solver strategies at your disposal, you can leverage symmetries and clustering techniques either fully automated or customized according to your specifications. This flexibility allows you to tailor your approach based on the specific characteristics of your system, optimizing performance without sacrificing accuracy.

The HQS NMR Tool is also an integral part of HQSpectrum, our end-to-end solution for NMR Spectra analysis. If you are interested in using this cloud service please request access by sending an email to hqspectrum@quantumsimulations.de.

If you are interested in the theory behind NMR or the math of how to calculate NMR spectra, take a look at the background chapter.

Getting started

To use the python API follow the installation steps outlined here.

For some of the functionalities of the HQS NMR Tool (especially the provided example NMR parameters), the RDKit cheminformatics package is required. It is strongly recommended to install it via the conda-forge channel to ensure the access to its latest version. Additionally it is highly recommended to install the Intel oneAPI Math-Kernel-Library (MKL) as otherwise performance will be critically impaired. However, these packages have to be installed manually. The easiest way to install these libraries is running the following command in an active conda environment:

conda install rdkit mkl

If you do not have conda available you can also install the packages via pip. This is not recommended as currently only an older version of RDkit is supported via pip and could cause issues in the future. Also it requires a numpy version smaller numpy 2.0:

pip install "numpy<2.0"
pip install rdkit

You can also install mkl via pip, however this requires also to set a symbolic link. Both steps can be conveniently performed using the python script ensure_mkl.py available with this repo. Just run:

python ensure_mkl.py

Usage

After you have installed the package the best way to learn about it is to go through our example notebooks. You can find information on how to download and run the examples in the basic usage section of our HQStage documentation.

Alternatively, you can get an overview of the HQS NMR Tool Python library in the components chapter.