Update README.md

README.md

@@ -20,9 +20,7 @@ configs:
 
 # PDB Chemical Component Dictionary
 
-This dataset contains a viewer-friendly Parquet table derived from the PDB Chemical Component Dictionary file in this repository. Each row is one chemical component from `components.cif.gz`.
-
-The original source file remains in the repository. The default `datasets` configuration uses the normalized Parquet files under `data/` so that the Hugging Face Dataset Viewer and `load_dataset()` can read component records directly.
+PDB-CCD is the Chemical Component Dictionary used by the Protein Data Bank to describe residues, modified residues, ligands, solvents, and other chemical components in macromolecular structures.
 
 ## Splits
 
@@ -176,6 +174,17 @@ print(recent[0]["component_id"], recent[0]["modified_date"])
 | `feature_values` | Feature values from `pdbx_chem_comp_feature`. |
 | `split_bucket` | Deterministic split bucket from `sha256(component_id) % 10`. |
 
-## Preparation
+# Citation
 
-The normalization script used to create the Parquet files is included at `scripts/prepare_pdb_ccd_dataset.py`.
+```
+@article{westbrook2015pdbccd,
+  title   = {The chemical component dictionary: complete descriptions of constituent molecules in experimentally determined 3D macromolecules in the Protein Data Bank},
+  author  = {Westbrook, John D. and Shao, Chuming and Feng, Zukang and Zhuravleva, Maria and Velankar, Sameer and Young, Jasmine},
+  journal = {Bioinformatics},
+  volume  = {31},
+  number  = {8},
+  pages   = {1274--1278},
+  year    = {2015},
+  doi     = {10.1093/bioinformatics/btu789}
+}
+```