[readme] add mention of Pyscf

README.md

@@ -17,7 +17,7 @@ The package implements a single optimization algorithm, which is an amalgam of s
 
 Several desirable features are missing at the moment but planned, some of them being actively worked on (help is always welcome): [crystal geometries](https://github.com/jhrmnn/pyberny/issues/5), [coordinate constraints](https://github.com/jhrmnn/pyberny/issues/14), [coordinate weighting](https://github.com/jhrmnn/pyberny/issues/32), [transition state search](https://github.com/jhrmnn/pyberny/issues/4).
 
-Berny is available in [ASE](https://wiki.fysik.dtu.dk/ase/dev/ase/optimize.html?highlight=berny#pyberny).
+Berny is available in [PySCF](https://sunqm.github.io/pyscf/geomopt.html#pyberny) and [ASE](https://wiki.fysik.dtu.dk/ase/dev/ase/optimize.html?highlight=berny#pyberny).
 
 ## Installing