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35 /*! \inpublicapi \file
37 * Implements nblib ForceCalculator
39 * \author Victor Holanda <victor.holanda@cscs.ch>
40 * \author Joe Jordan <ejjordan@kth.se>
41 * \author Prashanth Kanduri <kanduri@cscs.ch>
42 * \author Sebastian Keller <keller@cscs.ch>
44 #ifndef NBLIB_FORCECALCULATOR_H
45 #define NBLIB_FORCECALCULATOR_H
47 #include "nblib/interactions.h"
48 #include "nblib/kerneloptions.h"
49 #include "nblib/simulationstate.h"
60 class GmxForceCalculator;
62 /*! \brief Setups up and computes forces using gromacs backend.
64 * The ForceCalculator uses the data in the SimulationState and NBKernelOptions to opaquely
65 * construct all gromacs data structures needed to perform nonbonded force calculations. It is
66 * costly to create this object since much of the SimulationState and NBKernelOptions has to be
67 * passed to the gromacs backend. However, once constructed, compute can be called repeatedly only
68 * paying the cost of the actual nonbonded force calculation. Repeated calls to compute on the same
69 * coordinates will always return the same forces (within precision), so the user must update the
70 * positions using the forces generated here to advance a simulation. If the coordinates move
71 * sufficiently far from their positions at construction time, the efficiency of the calculation
72 * will suffer. To alleviate this, the user can call updatePairList.
75 class ForceCalculator final
78 ForceCalculator(const SimulationState& system, const NBKernelOptions& options);
82 /*! \brief Dispatch the nonbonded force kernels and reduce the forces
84 * This function zeroes out all values in the passed in forces buffer, so it can be regarded as
85 * an output only param.
87 * \param[in] coordinates to be used for the force calculation
88 * \param[out] forces buffer to store the output forces
90 void compute(gmx::ArrayRef<const Vec3> coordinates, gmx::ArrayRef<Vec3> forces);
92 /*! \brief Puts particles on a grid based on bounds specified by the box
94 * As compute is called repeatedly, the particles drift apart and the force computation becomes
95 * progressively less efficient. Calling this function recomputes the particle-particle pair
96 * lists so that computation can proceed efficiently. Should be called around every 100 steps.
98 * \param particleInfoAllVdW The types of the particles to be placed on grids
99 * \param coordinates The coordinates to be placed on grids
100 * \param[in] box The system simulation box
102 void updatePairList(gmx::ArrayRef<const int64_t> particleInfoAllVdW,
103 gmx::ArrayRef<Vec3> coordinates,
107 //! GROMACS force calculator to compute forces
108 std::unique_ptr<GmxForceCalculator> gmxForceCalculator_;
113 #endif // NBLIB_FORCECALCULATOR_H