First design of MD capability in Magpie (idaholab#367)

include/userobjects/LAMMPSFileRunner.h

@@ -0,0 +1,67 @@
+/**********************************************************************/
+/*                     DO NOT MODIFY THIS HEADER                      */
+/* MAGPIE - Mesoscale Atomistic Glue Program for Integrated Execution */
+/*                                                                    */
+/*            Copyright 2017 Battelle Energy Alliance, LLC            */
+/*                        ALL RIGHTS RESERVED                         */
+/**********************************************************************/
+
+#ifndef LAMMPSFILERUNNER_H
+#define LAMMPSFILERUNNER_H
+
+#include "MDRunBase.h"
+
+class LAMMPSFileRunner;
+
+template <>
+InputParameters validParams<LAMMPSFileRunner>();
+
+/**
+ * Reads lammps dump files to emulate MD simulation
+ */
+class LAMMPSFileRunner : public MDRunBase
+{
+public:
+  LAMMPSFileRunner(const InputParameters & parameters);
+
+  virtual void initialize() override {}
+  virtual void execute() override {}
+  virtual void finalize() override {}
+  virtual void initialSetup() override;
+
+  virtual void updateParticleList() override;
+
+protected:
+  /// reads a LAMMPS file
+  void readLAMMPSFile(FileName filename);
+
+  /// reads two LAMMPS files and interpolates times
+  void readLAMMPSFileHistory(std::pair<FileName, FileName> filenames,
+                             std::pair<Real, Real> timestamps,
+                             Real current_time);
+
+  /// helper function that finds two files, one right before and one right after md_time
+  void findBracketingLAMMPSFiles(Real md_time,
+                                 std::pair<std::string, std::string> & filenames,
+                                 std::pair<Real, Real> & timestamps);
+
+  /// whether a sequence of input files or a single input file is read
+  bool _time_sequence;
+
+  /// name of LAMMPS file or file base if _time_sequence == true
+  FileName _lammps_file;
+
+  /// column of , y, z coordinate in LAMMPS files
+  std::vector<unsigned int> _pos_columns;
+
+  /// get velocity from file or compute it from positions
+  bool _velocity_from_file;
+
+  /// column of , y, z coordinate in LAMMPS files
+  std::vector<unsigned int> _vel_columns;
+
+  /// Conversion from FEM time to MD time_stamp
+  Function * _time_conversion;
+};
+
+#endif // LAMMPSFILERUNNER_H

include/userobjects/MDRunBase.h

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+/**********************************************************************/
+/*                     DO NOT MODIFY THIS HEADER                      */
+/* MAGPIE - Mesoscale Atomistic Glue Program for Integrated Execution */
+/*                                                                    */
+/*            Copyright 2017 Battelle Energy Alliance, LLC            */
+/*                        ALL RIGHTS RESERVED                         */
+/**********************************************************************/
+
+#ifndef MDRUNBASE_H
+#define MDRUNBASE_H
+
+#include "GeneralUserObject.h"
+#include "KDTree.h"
+#include "libmesh/bounding_box.h"
+
+class MDRunBase;
+class MooseMesh;
+
+template <>
+InputParameters validParams<MDRunBase>();
+
+/**
+ * Base class for molecular dynamics runs in Magpie
+ */
+class MDRunBase : public GeneralUserObject
+{
+public:
+  MDRunBase(const InputParameters & parameters);
+
+  void initialSetup() override;
+  void timestepSetup() override;
+
+  class MDParticles
+  {
+  public:
+    /// particle's position and history
+    std::vector<Point> pos;
+
+    /// particle's velocity
+    std::vector<Point> vel;
+
+    /// the id of particle in the MD calculation
+    std::vector<unsigned int> id;
+
+    /// the mesh element the particles are in
+    std::vector<dof_id_type> elem_id;
+  };
+
+protected:
+  /// call back function to update the particle list
+  virtual void updateParticleList() = 0;
+
+  /// updates the KDTree object
+  void updateKDTree();
+
+  /// map MDParticles to elements
+  void mapMDParticles();
+
+  /// The Mesh we're using
+  MooseMesh & _mesh;
+
+  /// dimension of the mesh
+  const unsigned int _dim;
+
+  /// dimension of the mesh
+  const unsigned int _nproc;
+
+  /// stores bounding boxes of all other processors
+  std::vector<BoundingBox> _bbox;
+
+  /// total number of particles
+  unsigned int _n_particles;
+
+  /// number of local particles
+  unsigned int _n_local_particles;
+
+  /// stores the location of
+  MDParticles _md_particles;
+
+  /// a map from elem pointer to particles in this element
+  std::map<dof_id_type, std::vector<unsigned int>> _elem_particles;
+
+  /// A KDTree object to handle md_particles
+  std::unique_ptr<KDTree> _kd_tree;
+};
+
+#endif // MDRUNBASE_H