diff --git a/backend/protzilla/data_analysis/geometry_operations.py b/backend/protzilla/data_analysis/geometry_operations.py
new file mode 100644
index 000000000..8fa702e3d
--- /dev/null
+++ b/backend/protzilla/data_analysis/geometry_operations.py
@@ -0,0 +1,188 @@
+import numpy as np
+import pandas as pd
+import trimesh
+from trimesh import Trimesh
+from trimesh.collision import CollisionManager
+
+
+def _resolve_chain_column(cif_df: pd.DataFrame) -> str | None:
+    """
+    Return the preferred chain identifier column if present in the CIF DataFrame.
+    """
+
+    if "_atom_site.label_asym_id" in cif_df.columns:
+        return "_atom_site.label_asym_id"
+    if "_atom_site.auth_asym_id" in cif_df.columns:
+        return "_atom_site.auth_asym_id"
+    return None
+
+
+def extract_points_from_cif(
+    cif_df: pd.DataFrame,
+    residue_range: tuple[int, int],
+    chain_id: str | None = None,
+) -> np.ndarray:
+    """
+    Extract Cartesian atom coordinates in a residue range from a CIF DataFrame.
+
+    :param cif_df: DataFrame containing mmCIF atom_site coordinates
+    :param residue_range: inclusive residue interval as [start, end]
+    :param chain_id: optional chain identifier. If given, the function will filter by
+    _atom_site.label_asym_id or _atom_site.auth_asym_id when available.
+    :return: array of n points und x, y, z coordinates. (n, 3)
+    :raises ValueError: if required columns are missing or too few points remain
+    """
+
+    required_columns = {
+        "_atom_site.label_seq_id",
+        "_atom_site.Cartn_x",
+        "_atom_site.Cartn_y",
+        "_atom_site.Cartn_z",
+    }
+    missing_columns = sorted(required_columns - set(cif_df.columns))
+    if missing_columns:
+        raise ValueError(
+            f"CIF DataFrame is missing required columns for 3D extraction: {missing_columns}"
+        )
+
+    start, end = residue_range
+    if start > end:
+        raise ValueError(
+            f"Invalid residue range {residue_range}. Start must be smaller than or equal to end."
+        )
+
+    filtered_df = cif_df.copy()
+
+    chain_column = _resolve_chain_column(filtered_df)
+    if chain_id is not None:
+        if chain_column is None:
+            raise ValueError(
+                "A chain_id was provided, but the CIF DataFrame has no chain identifier column."
+            )
+        filtered_df = filtered_df[filtered_df[chain_column] == chain_id]
+
+    residue_ids = filtered_df["_atom_site.label_seq_id"].astype(int)
+    filtered_df = filtered_df[(residue_ids >= start) & (residue_ids <= end)]
+
+    points = (
+        filtered_df[
+            [
+                "_atom_site.Cartn_x",
+                "_atom_site.Cartn_y",
+                "_atom_site.Cartn_z",
+            ]
+        ]
+        .astype(float)
+        .drop_duplicates()
+        .to_numpy()
+    )
+
+    if len(points) == 0:
+        raise ValueError("No atom coordinates found.")
+
+    return points
+
+
+def build_convex_hull(points: np.ndarray) -> Trimesh:
+    """
+    Build a 3D convex hull mesh from a point cloud.
+    """
+
+    if points.ndim != 2 or points.shape[1] != 3:
+        raise ValueError(
+            f"Expected points with shape (n, 3), got array with shape {points.shape}."
+        )
+
+    if len(points) < 4:
+        raise ValueError(
+            "At least four distinct points are required to build a 3D convex hull."
+        )
+
+    return trimesh.convex.convex_hull(
+        points, qhull_options="QJ"
+    )  # Maybe QJ is stupid here? Ill have to look into it
+
+
+def meshes_intersect(
+    mesh_a: Trimesh, mesh_b: Trimesh, distance_tolerance: float = 1e-9
+) -> bool:
+    """
+    Determine whether two triangle meshes intersect or touch.
+    """
+
+    manager = CollisionManager()
+    manager.add_object("mesh_a", mesh_a)
+    return manager.min_distance_single(mesh_b) <= distance_tolerance
+
+
+def meshes_distance(mesh_a: Trimesh, mesh_b: Trimesh) -> float:
+    """
+    Calculate the minimum euclidean distance between two triangle meshes.
+    """
+
+    manager = CollisionManager()
+    manager.add_object("mesh_a", mesh_a)
+    distance = float(manager.min_distance_single(mesh_b))
+    return max(distance, 0.0)
+
+
+def bodies_intersect_from_cif(
+    cif_df: pd.DataFrame,
+    residue_range_a: tuple[int, int],
+    residue_range_b: tuple[int, int],
+    chain_id: str | None = None,
+) -> dict:
+    """
+    Build two convex bodies from CIF residue ranges and test whether they intersect.
+
+    :param cif_df: DataFrame containing mmCIF atom_site coordinates
+    :param residue_range_a: inclusive residue range for the first body
+    :param residue_range_b: inclusive residue range for the second body
+    :param chain_id: optional chain identifier used for both bodies
+    :return: summary dictionary with hull sizes and the intersection result
+    """
+
+    points_a = extract_points_from_cif(cif_df, residue_range_a, chain_id=chain_id)
+    points_b = extract_points_from_cif(cif_df, residue_range_b, chain_id=chain_id)
+
+    hull_a = build_convex_hull(points_a)
+    hull_b = build_convex_hull(points_b)
+
+    return {
+        "intersects": meshes_intersect(hull_a, hull_b),
+        "n_atoms_a": len(points_a),
+        "n_atoms_b": len(points_b),
+        "n_hull_vertices_a": len(hull_a.vertices),
+        "n_hull_vertices_b": len(hull_b.vertices),
+    }
+
+
+def bodies_distance_from_cif(
+    cif_df: pd.DataFrame,
+    residue_range_a: tuple[int, int],
+    residue_range_b: tuple[int, int],
+    chain_id: str | None = None,
+) -> dict:
+    """
+    Build two convex bodies from CIF residue ranges and calculate their distance.
+
+    :param cif_df: DataFrame containing mmCIF atom_site coordinates
+    :param residue_range_a: inclusive residue range for the first body
+    :param residue_range_b: inclusive residue range for the second body
+    :param chain_id: optional chain identifier used for both bodies
+    :return: summary dictionary with hull sizes and the minimum distance
+    """
+
+    points_a = extract_points_from_cif(cif_df, residue_range_a, chain_id=chain_id)
+    points_b = extract_points_from_cif(cif_df, residue_range_b, chain_id=chain_id)
+
+    hull_a = build_convex_hull(points_a)
+    hull_b = build_convex_hull(points_b)
+
+    return {
+        "distance": meshes_distance(hull_a, hull_b),
+        "n_atoms_a": len(points_a),
+        "n_atoms_b": len(points_b),
+        "n_hull_vertices_a": len(hull_a.vertices),
+        "n_hull_vertices_b": len(hull_b.vertices),
+    }
diff --git a/requirements.txt b/requirements.txt
index b9119f4a9..992012ba4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -32,6 +32,7 @@ pytest-django==4.11.1
 pytest-order==1.3.0
 PyYAML==6.0.3
 py7zr!=1.1.2
+python-fcl==0.7.0.11
 requests==2.32.5
 restring==0.1.21
 scikit-learn==1.7.2
@@ -40,6 +41,7 @@ seaborn==0.13.2
 sphinx==8.2.3
 sphinx-autoapi==3.6.1
 statsmodels==0.14.5
+trimesh==4.11.5
 tqdm==4.67.1
 tzlocal==5.3.1
 umap-learn==0.5.9.post2