Document 3D structure access (Files tab + hf_hub_download)

README.md

@@ -64,18 +64,38 @@ structure). 2D depictions are embedded inline; 3D conformers ship as repo files.
 
 ## 3D structures
 
-3D conformers (RDKit ETKDGv3 + MMFF94/UFF) are shipped under `structures_3d/`,
-one `.xyz`, `.sdf`, and `.pdb` per molecule, named by InChIKey. Resolve them via
-`host_3d_basename` / `guest_3d_basename`:
+3D conformers (RDKit ETKDGv3 + MMFF94/UFF) are shipped as repo files under
+`structures_3d/`, one `.xyz`, `.sdf`, and `.pdb` per molecule, named by InChIKey
+(1,399 molecules x 3 formats = 4,197 files).
+
+> **Note.** The 3D files are **not shown in the dataset viewer** (XYZ/SDF/PDB are
+> not a HuggingFace column type). They live under the **Files and versions** tab.
+> Each record links to them through the `host_3d_basename` and `guest_3d_basename`
+> columns, where the file path is `structures_3d/<basename>.{xyz,sdf,pdb}`.
+
+Download a record's 3D structures programmatically:
 
 ```python
 from datasets import load_dataset
+from huggingface_hub import hf_hub_download
+
 ds = load_dataset("SupraBench/Binding-Affinity", split="train")
 row = ds[0]
-host_xyz  = f"structures_3d/{row['host_3d_basename']}.xyz"
-guest_sdf = f"structures_3d/{row['guest_3d_basename']}.sdf"
+
+# host conformer (XYZ); swap the extension for .sdf or .pdb
+host_xyz = hf_hub_download(
+    repo_id="SupraBench/Binding-Affinity", repo_type="dataset",
+    filename=f"structures_3d/{row['host_3d_basename']}.xyz",
+)
+guest_sdf = hf_hub_download(
+    repo_id="SupraBench/Binding-Affinity", repo_type="dataset",
+    filename=f"structures_3d/{row['guest_3d_basename']}.sdf",
+)
 ```
 
+An empty `host_3d_basename` / `guest_3d_basename` means no 3D conformer is
+available for that molecule (see *Known limitations* and `failures.csv`).
+
 ## Resolution & validation
 
 SMILES were resolved through a cascade (local SupraBank/CB7 dictionaries -> InChI