ChemApp for Python with Python virtualenv

The following procedures were written for Windows and Linux users that prefer using Python virtual environments without the use of an IDE.

Windows

Download Python and Pip.

Download and install Python as explained in the “ChemApp for Python with a Bare Python Installation” section. Also complete the “Additional installations” mentioned in this section to install “pip” and “setuptools”.
Make a virtual environment.

A step-by-step guide on creating a virtual environment can be found here. In this example, we will name our virtual environment “chemapp-light”.
Download ChemApp for Python’s free Light edition.

Download and install ChemApp for Python Light as explained in the “Installing ChemApp for Python on Bare Python” section. In this example, ChemApp for Python was downloaded to
```
C:\Python\Scripts\python-packages\
```
Install ChemApp for Python in a virtual environment.

Activate the newly created virtual environment with the following command:
```
.\chemapp-light\Scripts\activate
```
ChemApp for Python can now be installed using
```
pip install C:\Python\Scripts\python-packages\``chemapp831.2.0-win-chemapp8.3.1-python3.12.7.tar.gz``'
```
pip list can be used to ensure that the chemapp package was successfully installed.

Linux

The procedure for installing ChemApp for Python on Linux using a Python virtual environment is as follows:

Install virtualenv.

In the terminal, run the following installation command:
```
pip install virtualenv
```
Add a new virtual environment.

Once the virtualenv installtion is completed it is required to create a virtual environment. The name of the virtual environment is determined by the user, for simplicity, my-chemapp-env is used to name the environment. The environment can be created in any directory with its specific file_path.
```
virtualenv file_path/my-chemapp-env
```
It is not necessary to add a file_path, then by default, the virtual environment will be created in the /home directory.
Activate the virtual environment.

To activate the virtual environment run the following command in the terminal.
```
source file_path/my-chemapp-env/bin/activate
```
Once the virtual environment is active, the name of the virtual environment will be displayed in closed brackets on the left-hand side of the terminal command line, e.g. (my-chemapp-env). To deactivate the environment simply run deactivate in the terminal command line.
Install the Python version.

To install the correct Python version type the following command in the terminal with the virtual environment active:
```
virtualenv --download python3.9.1
```
Install ChemApp for Python.

ChemApp for Python Light can be downloaded from the GTT Technologies website for the Linux version. You will need to cd file_path to the directory where the ChemApp for Python distribution package is stored. Install the ChemApp for Python package with the following command in the terminal:
```
pip install ``chemapp831.2.0-linux-chemapp8.3.1-python3.12.7.tar.gz``
```