Add arXiv DOI (2603.01834)

README.md

@@ -20,6 +20,7 @@ Dataset for classifying crystal system (7 classes) from chemical formula.
 @article{venugopal2026probing,
   title={Probing Materials Intelligence in LLMs: From Latent Embeddings to Reliable Predictions},
   author={Venugopal, Vineeth and Mahjoubi, Soroush and Olivetti, Elsa},
+  journal={arXiv preprint arXiv:2603.01834},
   year={2026}
 }
 ```