@@ -3,6 +3,8 @@
 
 #include <memory>
 
+#include "pugixml.hpp"
+
 #include "openmc/distribution.h"
 #include "openmc/position.h"
 
@@ -16,14 +18,15 @@ namespace openmc {
 class UnitSphereDistribution {
 public:
   UnitSphereDistribution() { };
-  explicit UnitSphereDistribution(Direction u) : u_ref{u} { };
+  explicit UnitSphereDistribution(Direction u) : u_ref_{u} { };
+  explicit UnitSphereDistribution(pugi::xml_node node);
   virtual ~UnitSphereDistribution() = default;
 
   //! Sample a direction from the distribution
   //! \return Direction sampled
   virtual Direction sample() const = 0;
 
-  Direction u_ref {0.0, 0.0, 1.0};  //!< reference direction
+  Direction u_ref_ {0.0, 0.0, 1.0};  //!< reference direction
 };
 
 //==============================================================================
@@ -33,6 +36,7 @@ class UnitSphereDistribution {
 class PolarAzimuthal : public UnitSphereDistribution {
 public:
   PolarAzimuthal(Direction u, UPtrDist mu, UPtrDist phi);
+  explicit PolarAzimuthal(pugi::xml_node node);
 
   //! Sample a direction from the distribution
   //! \return Direction sampled
@@ -62,6 +66,7 @@ class Isotropic : public UnitSphereDistribution {
 class Monodirectional : public UnitSphereDistribution {
 public:
   Monodirectional(Direction u) : UnitSphereDistribution{u} { };
+  explicit Monodirectional(pugi::xml_node node) : UnitSphereDistribution{node} { };
 
   //! Sample a direction from the distribution
   //! \return Sampled direction
 
@@ -43,7 +43,7 @@ class CartesianIndependent : public SpatialDistribution {
 
 class SpatialBox : public SpatialDistribution {
 public:
-  explicit SpatialBox(pugi::xml_node node);
+  explicit SpatialBox(pugi::xml_node node, bool fission=false);
 
   //! Sample a position from the distribution
   //! \return Sampled position
@@ -60,6 +60,7 @@ class SpatialBox : public SpatialDistribution {
 
 class SpatialPoint : public SpatialDistribution {
 public:
+  SpatialPoint() : r_{} { };
   explicit SpatialPoint(pugi::xml_node node);
 
   //! Sample a position from the distribution
 
@@ -4,27 +4,64 @@
 #include <cmath>     // for sqrt, sin, cos, max
 
 #include "openmc/constants.h"
+#include "openmc/error.h"
 #include "openmc/math_functions.h"
 #include "openmc/random_lcg.h"
+#include "openmc/xml_interface.h"
 
 namespace openmc {
 
+//==============================================================================
+// UnitSphereDistribution implementation
+//==============================================================================
+
+UnitSphereDistribution::UnitSphereDistribution(pugi::xml_node node)
+{
+  // Read reference directional unit vector
+  if (check_for_node(node, "reference_uvw")) {
+    auto u_ref = get_node_array<double>(node, "reference_uvw");
+    if (u_ref.size() != 3)
+      fatal_error("Angular distribution reference direction must have "
+                  "three parameters specified.");
+    u_ref_ = Direction(u_ref.data());
+  }
+}
+
+
 //==============================================================================
 // PolarAzimuthal implementation
 //==============================================================================
 
 PolarAzimuthal::PolarAzimuthal(Direction u, UPtrDist mu, UPtrDist phi) :
   UnitSphereDistribution{u}, mu_{std::move(mu)}, phi_{std::move(phi)} { }
 
+PolarAzimuthal::PolarAzimuthal(pugi::xml_node node)
+  : UnitSphereDistribution{node}
+{
+  if (check_for_node(node, "mu")) {
+    pugi::xml_node node_dist = node.child("mu");
+    mu_ = distribution_from_xml(node_dist);
+  } else {
+    mu_ = UPtrDist{new Uniform(-1., 1.)};
+  }
+
+  if (check_for_node(node, "phi")) {
+    pugi::xml_node node_dist = node.child("phi");
+    phi_ = distribution_from_xml(node_dist);
+  } else {
+    phi_ = UPtrDist{new Uniform(0.0, 2.0*PI)};
+  }
+}
+
 Direction PolarAzimuthal::sample() const
 {
   // Sample cosine of polar angle
   double mu = mu_->sample();
-  if (mu == 1.0) return u_ref;
+  if (mu == 1.0) return u_ref_;
 
   // Sample azimuthal angle
   double phi = phi_->sample();
-  return rotate_angle(u_ref, mu, &phi);
+  return rotate_angle(u_ref_, mu, &phi);
 }
 
 //==============================================================================
@@ -45,7 +82,7 @@ Direction Isotropic::sample() const
 
 Direction Monodirectional::sample() const
 {
-  return u_ref;
+  return u_ref_;
 }
 
 } // namespace openmc
@@ -55,7 +55,8 @@ Position CartesianIndependent::sample() const
 // SpatialBox implementation
 //==============================================================================
 
-SpatialBox::SpatialBox(pugi::xml_node node)
+SpatialBox::SpatialBox(pugi::xml_node node, bool fission)
+  : only_fissionable_{fission}
 {
   // Read lower-right/upper-left coordinates
   auto params = get_node_array<double>(node, "parameters");
Original file line number	Diff line number	Diff line change
`@@ -55,7 +55,8 @@ Position CartesianIndependent::sample() const`
`55`	`55`	`// SpatialBox implementation`
`56`	`56`	`//==============================================================================`
`57`	`57`
`58`		`-SpatialBox::SpatialBox(pugi::xml_node node)`
	`58`	`+SpatialBox::SpatialBox(pugi::xml_node node, bool fission)`
	`59`	`+ : only_fissionable_{fission}`
`59`	`60`	`{`
`60`	`61`	`// Read lower-right/upper-left coordinates`
`61`	`62`	`auto params = get_node_array<double>(node, "parameters");`