diff --git a/biblio.bib b/biblio.bib
index fc5ef8c..1b989a6 100644
--- a/biblio.bib
+++ b/biblio.bib
@@ -443,3 +443,15 @@
 	Title = {The first twenty-eight gas-phase proton hydration energies},
 	Volume = {182},
 	Year = {1991}}
+
+@article{kapil2019pi,
+  title={i-PI 2.0: A universal force engine for advanced molecular simulations},
+  author={Kapil, Venkat and Rossi, Mariana and Marsalek, Ondrej and Petraglia, Riccardo and Litman, Yair and Spura, Thomas and Cheng, Bingqing and Cuzzocrea, Alice and Mei{\ss}ner, Robert H and Wilkins, David M and others},
+  journal={Computer Physics Communications},
+  volume={236},
+  pages={214--223},
+  year={2019},
+  publisher={Elsevier}
+}
+
+