Rename ParticlePdg to PDGNumber

paulromano · Feb 3, 2026 · Jan 23, 2026 · Jan 23, 2026 · Jan 27, 2026 · Jan 27, 2026
commit 49e189c6945ba68f4c3dc79add56c44473d7af07
diff --git a/include/openmc/event.h b/include/openmc/event.h
@@ -23,10 +23,10 @@ namespace openmc {
 // may not result in any benefits if not enough particles are present for them
 // to achieve consistent locality improvements.
 struct EventQueueItem {
-  int64_t idx;       //!< particle index in event-based particle buffer
-  ParticlePdg type;  //!< particle PDG
-  int64_t material;  //!< material that particle is in
-  double E;          //!< particle energy
+  int64_t idx;      //!< particle index in event-based particle buffer
+  PDGNumber type;   //!< particle PDG
+  int64_t material; //!< material that particle is in
+  double E;         //!< particle energy
 
   // Constructors
   EventQueueItem() = default;

diff --git a/include/openmc/particle.h b/include/openmc/particle.h
@@ -49,7 +49,7 @@ class Particle : public ParticleData {
   //! \param E Energy of the secondary particle in [eV]
   //! \param type Particle type
   //! \return Whether a secondary particle was created
-  bool create_secondary(double wgt, Direction u, double E, ParticlePdg type);
+  bool create_secondary(double wgt, Direction u, double E, PDGNumber type);
 
   //! split a particle
   //
@@ -127,9 +127,9 @@ class Particle : public ParticleData {
 //! Functions
 //============================================================================
 
-std::string particle_pdg_to_str(ParticlePdg type);
+std::string particle_pdg_to_str(PDGNumber type);
 
-ParticlePdg str_to_particle_pdg(std::string_view str);
+PDGNumber str_to_particle_pdg(std::string_view str);
 
 void add_surf_source_to_bank(Particle& p, const Surface& surf);
 

diff --git a/include/openmc/particle_data.h b/include/openmc/particle_data.h
@@ -46,7 +46,7 @@ struct SourceSite {
   double wgt {1.0};
   int delayed_group {0};
   int surf_id {SURFACE_NONE};
-  ParticlePdg particle;
+  PDGNumber particle;
 
   // Extra attributes that don't show up in source written to file
   int parent_nuclide {-1};
@@ -68,7 +68,7 @@ struct CollisionTrackSite {
   int material_id {0};
   int universe_id {0};
   int n_collision {0};
-  ParticlePdg particle;
+  PDGNumber particle;
   int64_t parent_id;
   int64_t progeny_id;
 };
@@ -87,7 +87,7 @@ struct TrackState {
 
 //! Full history of a single particle's track states
 struct TrackStateHistory {
-  ParticlePdg particle;
+  PDGNumber particle;
   std::vector<TrackState> states;
 };
 
@@ -494,7 +494,7 @@ class ParticleData : public GeometryState {
   MacroXS macro_xs_;
   CacheDataMG mg_xs_cache_;
 
-  ParticlePdg type_ {PDG_NEUTRON};
+  PDGNumber type_ {PDG_NEUTRON};
 
   double E_;
   double E_last_;
@@ -590,10 +590,10 @@ class ParticleData : public GeometryState {
   const CacheDataMG& mg_xs_cache() const { return mg_xs_cache_; }
 
   // Particle type (n, p, e, gamma, etc)
-  ParticlePdg& type() { return type_; }
-  const ParticlePdg& type() const { return type_; }
-  ParticlePdg& pdg() { return type_; }
-  const ParticlePdg& pdg() const { return type_; }
+  PDGNumber& type() { return type_; }
+  const PDGNumber& type() const { return type_; }
+  PDGNumber& pdg() { return type_; }
+  const PDGNumber& pdg() const { return type_; }
 
   // Current particle energy, energy before collision,
   // and corresponding multigroup group indices. Energy

diff --git a/include/openmc/particle_pdg.h b/include/openmc/particle_pdg.h
@@ -19,28 +19,28 @@ namespace openmc {
 // Canonical PDG particle identifier (standard-layout, trivially copyable)
 //------------------------------------------------------------------------------
 
-struct ParticlePdg {
+struct PDGNumber {
   int32_t value;
 };
 
-static_assert(std::is_standard_layout_v<ParticlePdg>,
-  "ParticlePdg must be standard-layout");
-static_assert(std::is_trivially_copyable_v<ParticlePdg>,
+static_assert(
+  std::is_standard_layout_v<PDGNumber>, "ParticlePdg must be standard-layout");
+static_assert(std::is_trivially_copyable_v<PDGNumber>,
   "ParticlePdg must be trivially copyable");
 static_assert(
-  offsetof(ParticlePdg, value) == 0, "ParticlePdg value must be at offset 0");
-static_assert(sizeof(ParticlePdg) == sizeof(int32_t),
+  offsetof(PDGNumber, value) == 0, "ParticlePdg value must be at offset 0");
+static_assert(sizeof(PDGNumber) == sizeof(int32_t),
   "ParticlePdg must be same size as int32_t");
 
-constexpr bool operator==(ParticlePdg lhs, ParticlePdg rhs)
+constexpr bool operator==(PDGNumber lhs, PDGNumber rhs)
 {
   return lhs.value == rhs.value;
 }
-constexpr bool operator!=(ParticlePdg lhs, ParticlePdg rhs)
+constexpr bool operator!=(PDGNumber lhs, PDGNumber rhs)
 {
   return lhs.value != rhs.value;
 }
-constexpr bool operator<(ParticlePdg lhs, ParticlePdg rhs)
+constexpr bool operator<(PDGNumber lhs, PDGNumber rhs)
 {
   return lhs.value < rhs.value;
 }
@@ -49,20 +49,20 @@ constexpr bool operator<(ParticlePdg lhs, ParticlePdg rhs)
 // PDG constants (canonical particle identity)
 //------------------------------------------------------------------------------
 
-inline constexpr ParticlePdg PDG_NEUTRON {2112};
-inline constexpr ParticlePdg PDG_PHOTON {22};
-inline constexpr ParticlePdg PDG_ELECTRON {11};
-inline constexpr ParticlePdg PDG_POSITRON {-11};
-inline constexpr ParticlePdg PDG_PROTON {2212};
-inline constexpr ParticlePdg PDG_DEUTERON {1000010020};
-inline constexpr ParticlePdg PDG_TRITON {1000010030};
-inline constexpr ParticlePdg PDG_ALPHA {1000020040};
+inline constexpr PDGNumber PDG_NEUTRON {2112};
+inline constexpr PDGNumber PDG_PHOTON {22};
+inline constexpr PDGNumber PDG_ELECTRON {11};
+inline constexpr PDGNumber PDG_POSITRON {-11};
+inline constexpr PDGNumber PDG_PROTON {2212};
+inline constexpr PDGNumber PDG_DEUTERON {1000010020};
+inline constexpr PDGNumber PDG_TRITON {1000010030};
+inline constexpr PDGNumber PDG_ALPHA {1000020040};
 
 //------------------------------------------------------------------------------
 // Transport indexing helpers (for dense arrays keyed by transport kind)
 //------------------------------------------------------------------------------
 
-constexpr int transport_index_from_pdg(ParticlePdg pdg)
+constexpr int transport_index_from_pdg(PDGNumber pdg)
 {
   switch (pdg.value) {
   case PDG_NEUTRON.value:
@@ -78,7 +78,7 @@ constexpr int transport_index_from_pdg(ParticlePdg pdg)
   }
 }
 
-constexpr bool is_transport_pdg(ParticlePdg pdg)
+constexpr bool is_transport_pdg(PDGNumber pdg)
 {
   return transport_index_from_pdg(pdg) != C_NONE;
 }
@@ -88,25 +88,25 @@ constexpr bool is_transport_pdg(ParticlePdg pdg)
 //------------------------------------------------------------------------------
 
 // Convert a particle identifier string to PDG.
-ParticlePdg str_to_particle_pdg(std::string_view str);
+PDGNumber str_to_particle_pdg(std::string_view str);
 
 // Convert PDG to a canonical string (known names or GNDS nuclide name).
-std::string particle_pdg_to_str(ParticlePdg pdg);
+std::string particle_pdg_to_str(PDGNumber pdg);
 
 // Legacy enum code (0..3) to PDG conversion
-ParticlePdg legacy_particle_code_to_pdg(int code);
+PDGNumber legacy_particle_code_to_pdg(int code);
 
 // GNDS nuclide name to PDG nuclear code (100ZZZAAAI)
-ParticlePdg particle_pdg_from_nuclide_name(std::string_view gnds);
+PDGNumber particle_pdg_from_nuclide_name(std::string_view gnds);
 
 // PDG nuclear code to GNDS nuclide name (e.g., "Fe57", "Am242_m1")
-std::string nuclide_name_from_particle_pdg(ParticlePdg pdg);
+std::string nuclide_name_from_particle_pdg(PDGNumber pdg);
 
 // Build a PDG nuclear code from Z, A, and isomer level
-ParticlePdg particle_pdg_from_zam(int Z, int A, int m);
+PDGNumber particle_pdg_from_zam(int Z, int A, int m);
 
 // Check for PDG nuclear code (100ZZZAAAI)
-bool is_nuclear_pdg(ParticlePdg pdg);
+bool is_nuclear_pdg(PDGNumber pdg);
 
 } // namespace openmc
 

diff --git a/include/openmc/reaction_product.h b/include/openmc/reaction_product.h
@@ -49,7 +49,7 @@ class ReactionProduct {
   //! \param[inout] seed Pseudorandom seed pointer
   void sample(double E_in, double& E_out, double& mu, uint64_t* seed) const;
 
-  ParticlePdg particle_;       //!< Particle PDG
+  PDGNumber particle_;         //!< Particle PDG
   EmissionMode emission_mode_; //!< Emission mode
   double decay_rate_; //!< Decay rate (for delayed neutron precursors) in [1/s]
   unique_ptr<Function1D> yield_;      //!< Yield as a function of energy

diff --git a/include/openmc/source.h b/include/openmc/source.h
@@ -127,7 +127,7 @@ class IndependentSource : public Source {
   SourceSite sample(uint64_t* seed) const override;
 
   // Properties
-  ParticlePdg particle_type() const { return particle_; }
+  PDGNumber particle_type() const { return particle_; }
 
   // Make observing pointers available
   SpatialDistribution* space() const { return space_.get(); }
@@ -148,11 +148,11 @@ class IndependentSource : public Source {
 
 private:
   // Data members
-  ParticlePdg particle_ {PDG_NEUTRON};            //!< Type of particle emitted
-  UPtrSpace space_;                               //!< Spatial distribution
-  UPtrAngle angle_;                               //!< Angular distribution
-  UPtrDist energy_;                               //!< Energy distribution
-  UPtrDist time_;                                 //!< Time distribution
+  PDGNumber particle_ {PDG_NEUTRON}; //!< Type of particle emitted
+  UPtrSpace space_;                  //!< Spatial distribution
+  UPtrAngle angle_;                  //!< Angular distribution
+  UPtrDist energy_;                  //!< Energy distribution
+  UPtrDist time_;                    //!< Time distribution
 };
 
 //==============================================================================

diff --git a/include/openmc/tallies/filter_particle.h b/include/openmc/tallies/filter_particle.h
@@ -37,15 +37,15 @@ class ParticleFilter : public Filter {
   //----------------------------------------------------------------------------
   // Accessors
 
-  const vector<ParticlePdg>& particles() const { return particles_; }
+  const vector<PDGNumber>& particles() const { return particles_; }
 
-  void set_particles(span<ParticlePdg> particles);
+  void set_particles(span<PDGNumber> particles);
 
 private:
   //----------------------------------------------------------------------------
   // Data members
 
-  vector<ParticlePdg> particles_;
+  vector<PDGNumber> particles_;
 };
 
 } // namespace openmc

diff --git a/include/openmc/weight_windows.h b/include/openmc/weight_windows.h
@@ -153,7 +153,7 @@ class WeightWindows {
 
   void set_bounds(span<const double> lower_bounds, double ratio);
 
-  void set_particle_type(ParticlePdg p_type);
+  void set_particle_type(PDGNumber p_type);
 
   double survival_ratio() const { return survival_ratio_; }
 
@@ -188,14 +188,14 @@ class WeightWindows {
   const xt::xtensor<double, 2>& upper_ww_bounds() const { return upper_ww_; }
   xt::xtensor<double, 2>& upper_ww_bounds() { return upper_ww_; }
 
-  ParticlePdg particle_type() const { return particle_type_; }
+  PDGNumber particle_type() const { return particle_type_; }
 
 private:
   //----------------------------------------------------------------------------
   // Data members
   int32_t id_;    //!< Unique ID
   int64_t index_; //!< Index into weight windows vector
-  ParticlePdg particle_type_ {
+  PDGNumber particle_type_ {
     PDG_NEUTRON};                //!< Particle type to apply weight windows to
   vector<double> energy_bounds_; //!< Energy boundaries [eV]
   xt::xtensor<double, 2> lower_ww_; //!< Lower weight window bounds (shape:

diff --git a/src/mcpl_interface.cpp b/src/mcpl_interface.cpp
@@ -321,7 +321,7 @@ inline void ensure_mcpl_ready_or_fatal()
 SourceSite mcpl_particle_to_site(const mcpl_particle_repr_t* particle_repr)
 {
   SourceSite site;
-  site.particle = ParticlePdg {static_cast<int32_t>(particle_repr->pdgcode)};
+  site.particle = PDGNumber {static_cast<int32_t>(particle_repr->pdgcode)};
 
   // Copy position and direction
   site.r.x = particle_repr->position[0];

diff --git a/src/particle.cpp b/src/particle.cpp
@@ -75,7 +75,7 @@ double Particle::speed() const
 }
 
 bool Particle::create_secondary(
-  double wgt, Direction u, double E, ParticlePdg type)
+  double wgt, Direction u, double E, PDGNumber type)
 {
   // If energy is below cutoff for this particle, don't create secondary
   // particle

diff --git a/src/particle_pdg.cpp b/src/particle_pdg.cpp
@@ -107,7 +107,7 @@ bool parse_gnds_nuclide(std::string_view name, int& Z, int& A, int& m)
 
 } // namespace
 
-ParticlePdg str_to_particle_pdg(std::string_view str)
+PDGNumber str_to_particle_pdg(std::string_view str)
 {
   std::string s {str};
   strtrim(s);
@@ -124,7 +124,7 @@ ParticlePdg str_to_particle_pdg(std::string_view str)
       throw std::invalid_argument {"Invalid PDG code: " + value_str};
     }
     int32_t value = std::stoi(value_str);
-    return ParticlePdg {value};
+    return PDGNumber {value};
   }
 
   if (lower == "neutron" || lower == "n")
@@ -146,13 +146,13 @@ ParticlePdg str_to_particle_pdg(std::string_view str)
 
   if (is_integer_string(s)) {
     int32_t value = std::stoi(s);
-    return ParticlePdg {value};
+    return PDGNumber {value};
   }
 
   return particle_pdg_from_nuclide_name(s);
 }
 
-std::string particle_pdg_to_str(ParticlePdg pdg)
+std::string particle_pdg_to_str(PDGNumber pdg)
 {
   if (pdg == PDG_NEUTRON)
     return "neutron";
@@ -172,7 +172,7 @@ std::string particle_pdg_to_str(ParticlePdg pdg)
   return "pdg:" + std::to_string(pdg.value);
 }
 
-ParticlePdg legacy_particle_code_to_pdg(int code)
+PDGNumber legacy_particle_code_to_pdg(int code)
 {
   switch (code) {
   case 0:
@@ -189,7 +189,7 @@ ParticlePdg legacy_particle_code_to_pdg(int code)
   }
 }
 
-ParticlePdg particle_pdg_from_nuclide_name(std::string_view gnds)
+PDGNumber particle_pdg_from_nuclide_name(std::string_view gnds)
 {
   int Z = 0;
   int A = 0;
@@ -200,7 +200,7 @@ ParticlePdg particle_pdg_from_nuclide_name(std::string_view gnds)
   return particle_pdg_from_zam(Z, A, m);
 }
 
-std::string nuclide_name_from_particle_pdg(ParticlePdg pdg)
+std::string nuclide_name_from_particle_pdg(PDGNumber pdg)
 {
   if (!is_nuclear_pdg(pdg)) {
     throw std::invalid_argument {
@@ -224,16 +224,16 @@ std::string nuclide_name_from_particle_pdg(ParticlePdg pdg)
   return name;
 }
 
-ParticlePdg particle_pdg_from_zam(int Z, int A, int m)
+PDGNumber particle_pdg_from_zam(int Z, int A, int m)
 {
   if (Z <= 0 || Z > 999 || A <= 0 || A > 999 || m < 0 || m > 9) {
     throw std::invalid_argument {"Invalid Z/A/m for nuclear PDG code."};
   }
   int32_t code = 1000000000 + Z * 10000 + A * 10 + m;
-  return ParticlePdg {code};
+  return PDGNumber {code};
 }
 
-bool is_nuclear_pdg(ParticlePdg pdg)
+bool is_nuclear_pdg(PDGNumber pdg)
 {
   int32_t code = pdg.value;
   if (code < 1000000000)

diff --git a/src/particle_restart.cpp b/src/particle_restart.cpp
@@ -56,7 +56,7 @@ void read_particle_restart(Particle& p, RunMode& previous_run_mode)
   int type;
   read_dataset(file_id, "type", type);
   p.type() = legacy_particle_codes ? legacy_particle_code_to_pdg(type)
-                                   : ParticlePdg {type};
+                                   : PDGNumber {type};
   read_dataset(file_id, "weight", p.wgt());
   read_dataset(file_id, "energy", p.E());
   read_dataset(file_id, "xyz", p.r());

diff --git a/src/source.cpp b/src/source.cpp
@@ -39,7 +39,7 @@ namespace openmc {
 
 namespace {
 
-void validate_pdg_or_fatal(ParticlePdg pdg, const std::string& context)
+void validate_pdg_or_fatal(PDGNumber pdg, const std::string& context)
 {
   if (is_transport_pdg(pdg))
     return;