diff --git a/.github/workflows/pytest.yml b/.github/workflows/pytest.yml
index b7ddda3..6e403a3 100644
--- a/.github/workflows/pytest.yml
+++ b/.github/workflows/pytest.yml
@@ -12,20 +12,25 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8, 3.9, 3.10, 3.11]
+        python-version: ["3.9", "3.10", "3.11"]
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
 
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
 
+      - name: Install Open Babel
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y openbabel
+
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install pytest
+          pip install -r requirements.txt
 
       - name: Run pytest
         run: pytest -q
diff --git a/.github/workflows/python-pytest.yml b/.github/workflows/python-pytest.yml
index 56aef5f..d40db4a 100644
--- a/.github/workflows/python-pytest.yml
+++ b/.github/workflows/python-pytest.yml
@@ -12,16 +12,21 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.11, 3.10, 3.9]
+        python-version: ["3.11", "3.10", "3.9"]
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
 
       - name: Set up Python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
 
+      - name: Install Open Babel
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y openbabel
+
       - name: Cache pip
         uses: actions/cache@v4
         with:
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..f0c84b1
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,46 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Virtual environments
+.venv/
+venv/
+ENV/
+env/
+
+# IDEs
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# Testing
+.pytest_cache/
+.coverage
+htmlcov/
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Tools
+actionlint
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..e9a91b7
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,2 @@
+pytest
+numpy