Add molecular orbital visualization tab

app.py

@@ -4,6 +4,9 @@ from rdkit.Chem import Descriptors, Draw, AllChem
 import cirpy
 import pubchempy as pcp
 from urllib.error import HTTPError, URLError
+import os
+import tempfile
+from pathlib import Path
 
 
 # RDKit API with multiple endpoints
@@ -83,6 +86,64 @@ def smiles_to_name(smiles: str) -> str:
     return f"No name available. Canonical SMILES: {canonical_smiles}"
 
 
+def smiles_to_molecular_orbitals(smiles: str) -> str:
+    """Generate HOMO/LUMO isosurfaces using Psikit and render with py3Dmol."""
+    mol = _mol_from_smiles(smiles)
+    if mol.GetNumAtoms() > 30:
+        raise gr.Error("Please provide a molecule with 30 atoms or fewer for orbital visualization.")
+
+    try:
+        from psikit import Psikit
+    except ImportError as exc:  # pragma: no cover - runtime dependency
+        raise gr.Error("Psikit is required for molecular orbital visualization.") from exc
+
+    try:
+        import py3Dmol
+    except ImportError as exc:  # pragma: no cover - runtime dependency
+        raise gr.Error("py3Dmol is required for molecular orbital visualization.") from exc
+
+    with tempfile.TemporaryDirectory() as tmpdir:
+        original_cwd = os.getcwd()
+        try:
+            os.chdir(tmpdir)
+            pk = Psikit()
+            pk.read_from_smiles(smiles)
+            pk.optimize()
+            pk.getMOview()
+
+            cube_candidates = sorted(Path(tmpdir).glob("Psi_a_*A.cube"))
+            if not cube_candidates:
+                raise gr.Error("Failed to generate molecular orbital cube files. Try a smaller molecule.")
+
+            mol_block = Chem.MolToMolBlock(pk.mol)
+        except Exception as exc:
+            raise gr.Error(f"Unable to compute molecular orbitals: {exc}") from exc
+        finally:
+            os.chdir(original_cwd)
+
+    def _render_cube(cube_path: Path, title: str) -> str:
+        cube_data = cube_path.read_text()
+        view = py3Dmol.view(width=500, height=400)
+        view.addModel(mol_block, "mol")
+        view.setStyle({"stick": {}})
+        isoval = 0.02
+        view.addVolumetricData(cube_data, "cube", {"isoval": isoval, "color": "blue", "opacity": 0.6})
+        view.addVolumetricData(cube_data, "cube", {"isoval": -isoval, "color": "red", "opacity": 0.6})
+        view.zoomTo()
+        return f"<h3>{title}</h3>" + view._make_html()
+
+    # First cube is HOMO, second is LUMO following psikit naming convention.
+    html_sections = []
+    labels = ["HOMO", "LUMO"]
+    for cube_file, label in zip(cube_candidates[:2], labels):
+        html_sections.append(_render_cube(cube_file, label))
+
+    if not html_sections:
+        raise gr.Error("Could not prepare HOMO/LUMO visualizations.")
+
+    return "".join(html_sections)
+
+
 def name_to_3d_molecule(name: str) -> str:
     """Convert chemical name to 3D molecule visualization"""
     try:
@@ -153,6 +214,14 @@ smiles_to_name_interface = gr.Interface(
     description="Convert a SMILES string to a chemical name.",
 )
 
+orbital_interface = gr.Interface(
+    fn=smiles_to_molecular_orbitals,
+    inputs=gr.Textbox(label="SMILES", placeholder="e.g., CC(=O)O"),
+    outputs=gr.HTML(label="Molecular Orbitals"),
+    api_name="smiles_to_mo",
+    description="Generate HOMO/LUMO isosurfaces using Psikit (CPU-intensive).",
+)
+
 name_interface = gr.Interface(
     fn=name_to_smiles,
     inputs=gr.Textbox(label="Chemical Name", placeholder="e.g., aspirin, caffeine, benzene"),
@@ -197,10 +266,20 @@ molecule_3d_interface = gr.Interface(
 
 
 demo = gr.TabbedInterface(
-    [name_interface, molecule_3d_interface, smiles_interface, smiles_to_name_interface, mw_interface, logp_interface, tpsa_interface],
+    [
+        name_interface,
+        molecule_3d_interface,
+        orbital_interface,
+        smiles_interface,
+        smiles_to_name_interface,
+        mw_interface,
+        logp_interface,
+        tpsa_interface,
+    ],
     [
         "Name to SMILES",
         "3D Molecule Viewer",
+        "Molecular Orbitals",
         "SMILES to Canonical",
         "SMILES to Name",
         "Molecular Weight",

requirements.txt

@@ -3,4 +3,7 @@ rdkit
 gradio==4.44.1
 huggingface_hub==0.19.4
 cirpy
-pubchempy
+pubchempy
+psikit
+psi4
+py3Dmol