Mention support for GPU4PySCF

README.md

@@ -90,8 +90,10 @@ License
     with the Skala-1.1 exchange-correlation functional. Note that, as
     with all density functionals, energy differences are predicted much
     more reliably than total energies of individual molecules.
-4.  The SCF implementation provided uses PySCF, which runs the
-    functional on CPU. We also provide a traced version of the Skala-1.1
+4.  The SCF implementation provided uses
+    [PySCF and GPU4PySCF](https://arxiv.org/abs/2603.14155),
+    which runs the functional on CPU and GPU.
+    We also provide a traced version of the Skala-1.1
     functional so that other, more optimized open-source SCF
     codes—including GPU-enabled ones—can integrate it into their
     pipelines, for instance through GauXC. A compatible fork of GauXC is