fix cached properties

Author: johannes-moegerle

src/rydstate/rydberg/rydberg_mqdt.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from functools import cached_property
 import logging
 from typing import TYPE_CHECKING, Any, Generic, TypeVar, overload
 
@@ -67,7 +68,7 @@ def norm(self) -> float:
         """Return the norm of the state (should be 1)."""
         return np.linalg.norm(self.coefficients)  # type: ignore [return-value]
 
-    @property
+    @cached_property
     def angular(self) -> AngularState[Any]:
         """Return the angular part of the MQDT state as an AngularState."""
         angular_kets = [ket.angular for ket in self.sqdt_states]

src/rydstate/rydberg/rydberg_sqdt.py

@@ -99,7 +99,7 @@ def __repr__(self) -> str:
     def __str__(self) -> str:
         return self.__repr__()
 
-    @property
+    @cached_property
     def radial(self) -> RadialKet:
         """The radial part of the Rydberg electron."""
         radial_ket = RadialKet(self.species, nu=self.nu, l_r=self.angular.l_r)