diff --git a/examples/lattice/geometry.xml b/examples/lattice/geometry.xml
deleted file mode 100644
index 8848e6810e..0000000000
--- a/examples/lattice/geometry.xml
+++ /dev/null
@@ -1,58 +0,0 @@
-<?xml version="1.0"?>
-<geometry>
-
-  <cell id="1">
-    <universe>0</universe>
-    <fill>111</fill>
-    <surfaces>1 -2 3 -4</surfaces>
-  </cell>
-  <cell id="100">
-    <universe>3</universe>
-    <material>40</material>
-    <surfaces>-5</surfaces>
-  </cell>
-  <cell id="101">
-    <universe>3</universe>
-    <material>41</material>
-    <surfaces>5</surfaces>
-  </cell>
-
-  <lattice id="111">
-    <type>rectangular</type>
-    <dimension>20 20</dimension>
-    <origin>-10.0 -10.0</origin>
-    <width>1.0 1.0</width>
-    <universes>
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-      3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
-    </universes>
-  </lattice>
-
-  <surface id="1" type="x-plane" coeffs="-9.9" boundary="vacuum" />
-  <surface id="2" type="x-plane" coeffs="9.9" boundary="vacuum" />
-  <surface id="3" type="y-plane" coeffs="-9.9" boundary="vacuum" />
-  <surface id="4" type="y-plane" coeffs="9.9" boundary="vacuum" />
-  <surface id="5">
-    <type>z-cylinder</type>
-    <coeffs>0.0 0.0 0.4</coeffs>
-  </surface>
-
-</geometry>
diff --git a/examples/lattice/materials.xml b/examples/lattice/materials.xml
deleted file mode 100644
index 88e20c69ef..0000000000
--- a/examples/lattice/materials.xml
+++ /dev/null
@@ -1,17 +0,0 @@
-<?xml version="1.0"?>
-<materials>
-
-<!-- Definition of materials -->
-  <material id="40">
-    <density value="4.5" units="g/cc" />
-    <nuclide name="U-235" xs="03c" ao="1.0" />
-  </material>
-
-  <material id="41">
-    <density value="1.0" units="g/cc" />
-    <nuclide name="H-1" xs="03c" ao="2.0" />
-    <nuclide name="O-16" xs="03c" ao="1.0" />
-    <sab name="lwe7" xs="00t" />
-  </material>
-
-</materials>
diff --git a/examples/lattice/nested/geometry.xml b/examples/lattice/nested/geometry.xml
new file mode 100644
index 0000000000..4ce62280a2
--- /dev/null
+++ b/examples/lattice/nested/geometry.xml
@@ -0,0 +1,45 @@
+<?xml version="1.0"?>
+<geometry>
+
+  <cell id="1"                fill="6" surfaces="1 -2 3 -4" />
+  <cell id="2"   universe="5" fill="4" surfaces="1 -2 3 -4" />
+  <cell id="101" universe="1" material="1" surfaces="-5" />
+  <cell id="102" universe="1" material="2" surfaces="5" />
+  <cell id="201" universe="2" material="1" surfaces="-6" />
+  <cell id="202" universe="2" material="2" surfaces="6" />
+  <cell id="301" universe="3" material="1" surfaces="-7" />
+  <cell id="302" universe="3" material="2" surfaces="7" />
+
+  <!-- 4 x 4 assembly -->
+  <lattice id="4">
+    <type>rectangular</type>
+    <dimension>2 2</dimension>
+    <origin>-1.0 -1.0</origin>
+    <width>1.0 1.0</width>
+    <universes>
+      1 2
+      2 3
+    </universes>
+  </lattice>
+
+  <!-- 4 x 4 core -->
+  <lattice id="6">
+    <type>rectangular</type>
+    <dimension>2 2</dimension>
+    <origin>-2.0 -2.0</origin>
+    <width>2.0 2.0</width>
+    <universes>
+      5 5
+      5 5
+    </universes>
+  </lattice>
+
+  <surface id="1" type="x-plane" coeffs="-2.0" boundary="vacuum" />
+  <surface id="2" type="x-plane" coeffs="2.0" boundary="vacuum" />
+  <surface id="3" type="y-plane" coeffs="-2.0" boundary="vacuum" />
+  <surface id="4" type="y-plane" coeffs="2.0" boundary="vacuum" />
+  <surface id="5" type="z-cylinder" coeffs="0.0 0.0 0.4" />
+  <surface id="6" type="z-cylinder" coeffs="0.0 0.0 0.3" />
+  <surface id="7" type="z-cylinder" coeffs="0.0 0.0 0.2" />
+
+</geometry>
diff --git a/examples/lattice/nested/materials.xml b/examples/lattice/nested/materials.xml
new file mode 100644
index 0000000000..3605c3ed65
--- /dev/null
+++ b/examples/lattice/nested/materials.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+<materials>
+
+  <default_xs>70c</default_xs>
+
+<!-- Definition of materials -->
+  <material id="1">
+    <density value="4.5" units="g/cc" />
+    <nuclide name="U-235" ao="1.0" />
+  </material>
+
+  <material id="2">
+    <density value="1.0" units="g/cc" />
+    <nuclide name="H-1"  ao="2.0" />
+    <nuclide name="O-16" ao="1.0" />
+    <sab name="lwtr" xs="10t" />
+  </material>
+
+</materials>
diff --git a/examples/lattice/nested/plot.xml b/examples/lattice/nested/plot.xml
new file mode 100644
index 0000000000..d6a0ca3cdf
--- /dev/null
+++ b/examples/lattice/nested/plot.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0"?>
+<plot>
+  <origin>0. 0. 0.</origin>
+  <width>3.999 3.999</width>
+  <pixel>0.01</pixel>
+</plot>
diff --git a/examples/lattice/settings.xml b/examples/lattice/nested/settings.xml
similarity index 63%
rename from examples/lattice/settings.xml
rename to examples/lattice/nested/settings.xml
index adbec19c7d..aa0b98ee4a 100644
--- a/examples/lattice/settings.xml
+++ b/examples/lattice/nested/settings.xml
@@ -1,11 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <settings>
 
-  <!-- Path for cross section library -->
-  <cross_sections>
-      /home/paulromano/openmc/cross_sections_serpent.xml
-  </cross_sections>
-
   <!-- Parameters for criticality calculation -->
   <criticality>
     <cycles>20</cycles>
@@ -13,10 +8,12 @@
     <particles>10000</particles>
   </criticality>
 
+  <verbosity>7</verbosity>
+
   <!-- Starting source -->
   <source>
     <type>box</type>
-    <coeffs>-4 -4 -4  4  4  4</coeffs>
+    <coeffs>-1 -1 -1  1  1  1</coeffs>
   </source>
 
 </settings>
diff --git a/examples/lattice/nested/tallies.xml b/examples/lattice/nested/tallies.xml
new file mode 100644
index 0000000000..a389dc905c
--- /dev/null
+++ b/examples/lattice/nested/tallies.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+<tallies>
+
+  <mesh id="1">
+    <type>rectangular</type>
+    <dimension>4 4</dimension>
+    <origin>-2.0 -2.0</origin>
+    <width>1.0 1.0</width>
+  </mesh>
+
+  <tally id="1">
+    <filters>
+      <mesh>1</mesh>
+    </filters>
+
+    <macros>total</macros>
+  </tally>
+
+</tallies>
\ No newline at end of file
diff --git a/examples/lattice/simple/geometry.xml b/examples/lattice/simple/geometry.xml
new file mode 100644
index 0000000000..4a77229392
--- /dev/null
+++ b/examples/lattice/simple/geometry.xml
@@ -0,0 +1,33 @@
+<?xml version="1.0"?>
+<geometry>
+
+  <cell id="1" fill="5" surfaces="1 -2 3 -4" />
+  <cell id="101" universe="1" material="1" surfaces="-5" />
+  <cell id="102" universe="1" material="2" surfaces="5" />
+  <cell id="201" universe="2" material="1" surfaces="-6" />
+  <cell id="202" universe="2" material="2" surfaces="6" />
+  <cell id="301" universe="3" material="1" surfaces="-7" />
+  <cell id="302" universe="3" material="2" surfaces="7" />
+
+  <lattice id="5">
+    <type>rectangular</type>
+    <dimension>4 4</dimension>
+    <origin>-2.0 -2.0</origin>
+    <width>1.0 1.0</width>
+    <universes>
+      1 2 1 2
+      2 3 2 3
+      1 2 1 2
+      2 3 2 3
+    </universes>
+  </lattice>
+
+  <surface id="1" type="x-plane" coeffs="-2.0" boundary="vacuum" />
+  <surface id="2" type="x-plane" coeffs="2.0" boundary="vacuum" />
+  <surface id="3" type="y-plane" coeffs="-2.0" boundary="vacuum" />
+  <surface id="4" type="y-plane" coeffs="2.0" boundary="vacuum" />
+  <surface id="5" type="z-cylinder" coeffs="0.0 0.0 0.4" />
+  <surface id="6" type="z-cylinder" coeffs="0.0 0.0 0.3" />
+  <surface id="7" type="z-cylinder" coeffs="0.0 0.0 0.2" />
+
+</geometry>
diff --git a/examples/lattice/simple/materials.xml b/examples/lattice/simple/materials.xml
new file mode 100644
index 0000000000..3605c3ed65
--- /dev/null
+++ b/examples/lattice/simple/materials.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+<materials>
+
+  <default_xs>70c</default_xs>
+
+<!-- Definition of materials -->
+  <material id="1">
+    <density value="4.5" units="g/cc" />
+    <nuclide name="U-235" ao="1.0" />
+  </material>
+
+  <material id="2">
+    <density value="1.0" units="g/cc" />
+    <nuclide name="H-1"  ao="2.0" />
+    <nuclide name="O-16" ao="1.0" />
+    <sab name="lwtr" xs="10t" />
+  </material>
+
+</materials>
diff --git a/examples/lattice/simple/plot.xml b/examples/lattice/simple/plot.xml
new file mode 100644
index 0000000000..d6a0ca3cdf
--- /dev/null
+++ b/examples/lattice/simple/plot.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0"?>
+<plot>
+  <origin>0. 0. 0.</origin>
+  <width>3.999 3.999</width>
+  <pixel>0.01</pixel>
+</plot>
diff --git a/examples/lattice/simple/settings.xml b/examples/lattice/simple/settings.xml
new file mode 100644
index 0000000000..aa0b98ee4a
--- /dev/null
+++ b/examples/lattice/simple/settings.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<settings>
+
+  <!-- Parameters for criticality calculation -->
+  <criticality>
+    <cycles>20</cycles>
+    <inactive>10</inactive>
+    <particles>10000</particles>
+  </criticality>
+
+  <verbosity>7</verbosity>
+
+  <!-- Starting source -->
+  <source>
+    <type>box</type>
+    <coeffs>-1 -1 -1  1  1  1</coeffs>
+  </source>
+
+</settings>
diff --git a/examples/lattice/simple/tallies.xml b/examples/lattice/simple/tallies.xml
new file mode 100644
index 0000000000..a389dc905c
--- /dev/null
+++ b/examples/lattice/simple/tallies.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+<tallies>
+
+  <mesh id="1">
+    <type>rectangular</type>
+    <dimension>4 4</dimension>
+    <origin>-2.0 -2.0</origin>
+    <width>1.0 1.0</width>
+  </mesh>
+
+  <tally id="1">
+    <filters>
+      <mesh>1</mesh>
+    </filters>
+
+    <macros>total</macros>
+  </tally>
+
+</tallies>
\ No newline at end of file