diff --git a/openmc/mgxs/mgxs.py b/openmc/mgxs/mgxs.py
index f4c569e164..f5e37680d8 100644
--- a/openmc/mgxs/mgxs.py
+++ b/openmc/mgxs/mgxs.py
@@ -359,6 +359,25 @@ class MultiGroupXS(object):
 
         cv.check_type('statepoint', statepoint, openmc.statepoint.StatePoint)
 
+        if not statepoint.with_summary:
+            msg = 'Unable to load data from a statepoint which has not been ' \
+                  'linked with a summary file'
+            raise ValueError(msg)
+
+        # Override the domain object that loaded from an OpenMC summary file
+        # NOTE: This is necessary for micro cross-sections which require
+        # the isotopic number densities as computed by OpenMC
+        if self.domain_type == 'cell':
+            self.domain = statepoint.summary.get_cell_by_id(self.domain.id)
+        elif self.domain_type == 'universe':
+            self.domain = statepoint.summary.get_universe_by_id(self.domain.id)
+        elif self.domain_type == 'material':
+            self.domain = statepoint.summary.get_material_by_id(self.domain.id)
+        else:
+            msg = 'Unable to load data from a statepoint for domain type {} ' \
+                  'which is not yet supported'.format(self.domain_type)
+            raise ValueError(msg)
+
         # Create Tallies to search for in StatePoint
         self.create_tallies()
 
@@ -424,6 +443,7 @@ class MultiGroupXS(object):
             raise ValueError(msg)
 
         cv.check_value('value', value, ['mean', 'std_dev', 'rel_err'])
+        cv.check_value('xs_type', xs_type, ['macro', 'micro'])
 
         filters = []
         filter_bins = []
@@ -631,6 +651,8 @@ class MultiGroupXS(object):
 
         """
 
+        cv.check_value('xs_type', xs_type, ['macro', 'micro'])
+
         if subdomains != 'all':
             cv.check_iterable_type('subdomains', subdomains, Integral)
         if nuclides != 'all':
@@ -1323,6 +1345,7 @@ class ScatterMatrixXS(MultiGroupXS):
             raise ValueError(msg)
 
         cv.check_value('value', value, ['mean', 'std_dev', 'rel_err'])
+        cv.check_value('xs_type', xs_type, ['macro', 'micro'])
 
         filters = []
         filter_bins = []
@@ -1384,6 +1407,8 @@ class ScatterMatrixXS(MultiGroupXS):
 
         """
 
+        cv.check_value('xs_type', xs_type, ['macro', 'micro'])
+
         if subdomains != 'all':
             cv.check_iterable_type('subdomains', subdomains, Integral)
         if nuclides != 'all':
@@ -1587,6 +1612,8 @@ class Chi(MultiGroupXS):
 
         """
 
+        cv.check_value('xs_type', xs_type, ['macro', 'micro'])
+
         if self.xs_type == 'micro' and xs_type == 'macro':
             raise NotImplementedError('Unable to compute macro Chi from micros')
 
diff --git a/openmc/statepoint.py b/openmc/statepoint.py
index f90e429cc0..f58994b8c7 100644
--- a/openmc/statepoint.py
+++ b/openmc/statepoint.py
@@ -82,8 +82,8 @@ class StatePoint(object):
         Indicate whether user-defined tallies are present
     version: tuple of int
         Version of OpenMC
-    with_summary : bool
-        Indicate whether statepoint data has been linked against a summary file
+    summary : None or openmc.summary.Summary
+        A summary object if the statepoint has been linked with a summary file
 
     """
 
@@ -104,7 +104,7 @@ class StatePoint(object):
         # Set flags for what data has been read
         self._meshes_read = False
         self._tallies_read = False
-        self._with_summary = False
+        self._summary = False
         self._global_tallies = None
 
     def close(self):
@@ -457,9 +457,16 @@ class StatePoint(object):
                 self._f['version_minor'].value,
                 self._f['version_release'].value)
 
+    @property
+    def summary(self):
+        return self._summary
+
     @property
     def with_summary(self):
-        return self._with_summary
+        if self.summary is None:
+            return False
+        else:
+            return True
 
     def get_tally(self, scores=[], filters=[], nuclides=[],
                   name=None, id=None, estimator=None):
@@ -628,4 +635,4 @@ class StatePoint(object):
                         material_ids.append(summary.materials[bin].id)
                     filter.bins = material_ids
 
-        self._with_summary = True
+        self._summary = summary
diff --git a/openmc/summary.py b/openmc/summary.py
index 2ae7464846..35aa703f55 100644
--- a/openmc/summary.py
+++ b/openmc/summary.py
@@ -83,7 +83,7 @@ class Summary(object):
             material = openmc.Material(material_id=material_id, name=name)
 
             # Set the Material's density to g/cm3 - this is what is used in OpenMC
-            material.set_density(density=density, units='g/cm3')
+            material.set_density(density=density, units='atom/b-cm')
 
             # Add all nuclides to the Material
             for fullname, density in zip(nuclides, nuc_densities):