Fix error in sams/components (#117)

* Fixing errors in param_spaces_classic.py

* Fix bug in sams/components.py

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Co-authored-by: Shreyas Tiruvaskar <sti50@bohr.canterbury.ac.nz>

Author: shreyas-tiruvaskar

holodeck/sams/components.py

@@ -164,7 +164,7 @@ def _phi_func(self, redz):
     def _mchar_func(self, redz):
         """See: [Chen2019]_ Eq.10 - NOTE: added `redz` term
         """
-        return self._mchar0 + self._mcharz * redz
+        return self._mchar0 * np.power(10, self._mcharz * redz)
 
     def _alpha_func(self, redz):
         """See: [Chen2019]_ Eq.11