Seeking Help with TorchANI Installation and ANIAngular/ANIRadial in Legolas

[Chemistry-Mike]

Hello,

I'm attempting to run the Legolas legolas.py script and am encountering a persistent ImportError related to torchani. I cloned the repository, installed the environment using conda (attempting both legolas_env.yaml and cpu_env.yaml). I ensured that the packages were installed, but when I installed torchANI, the script consistently fails on the line: from torchani.aev import AEVComputer, ANIAngular, ANIRadial.

I've attempted several steps to resolve this, suspecting a dependency mismatch. Here is a summary of the environment setups and installation attempts I've tried:

[1] Attempt with Python 3.10:

    I began by using python==3.10 and torchani==0.9. This immediately produced the ImportError.
    I also tried to install torchani==0.9.1 but pip indicated no matching distribution for that version.
    I then created a new Conda environment from a provided cpu_env.yaml file, which ended up installing torchani==2.2.4. This also produced the same ImportError, as the ANIAngular class was removed in torchani 2.0.

[2] Attempt with Python 3.7 (more compatible):

    I created a clean Conda environment with python==3.7.
    I installed all required dependencies incrementally: numpy, pandas, mdtraj, and biopython. The script progressed past each import line.
    I then installed torchani==0.9 and torch==1.5.0 to ensure version compatibility.
    Despite these steps, the script still failed with the same ImportError: cannot import name 'ANIAngular' from 'torchani.aev'.

It seems that even when I explicitly install torchani==0.9 using pip, the package that is installed does not contain the ANIAngular class. This is perplexing, as this class should exist in the 0.9 version of the library.

Could you please confirm the exact versions of torchani and torch that are known to be compatible with this script? Is there a specific channel or installation method I should be using? Any assistance you can provide would be greatly appreciated.

Thank you for your time and for creating Legolas.

Best,

Michael

[IgnacioJPickering]

Hello! I don't think the ANIAngular and ANIRadial classes exist in torchani==0.9 version of the lib. now that TorchANI 2.0 is public, I can update the repo so that it pulls the latest TorchANI version by default. For now you can install TorchANI 2.0 from source, just follow the instructions in the readme. I will try to get to this in the coming days

[IgnacioJPickering]

Hello @Chemistry-Mike I've updated the repo with new installation instructions.

Installation should be seamless now.

git cone git@github.com:roitberg-group/legolas.git
cd legolas
conda env create --file legolas_env.yaml
conda activate legolas
ani build-extensions  # Not required but recommended

Just in case, please don't use torchani from conda, since that package is unmaintained. The latest torchani (which is compatible with legolas) is 2.7

To update to the latest torchani version you can run pip install --upgrade torchani I recommend you use torch 2.8 and CUDA Toolkit 12.8 or 12.9 although other configurations will also work.

I will keep this issue open for now, let me know if you could install it!