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37 #ifndef GMX_MDLIB_NSGRID_H
38 #define GMX_MDLIB_NSGRID_H
42 #include "gromacs/math/vectypes.h"
43 #include "gromacs/utility/real.h"
46 struct gmx_domdec_zones_t;
53 int nr; // Total number of charge groups
54 int nboundeddim; // The number of bounded dimensions
55 int npbcdim; // The number of dimensions with pbc
56 int ncg_ideal; // The ideal number of cg's per cell
57 ivec n; // The dimension of the grid
58 int ncells; // Total number of cells
59 int cells_nalloc; // Allocation size of index and nra
60 ivec ncpddc; // The number of cells per DD cell
61 rvec cell_size; // The size of the cells
62 rvec cell_offset; // The offset of the cell (0,0,0)
63 int* cell_index; // The cell number of each cg
64 int* index; // The index into a for each cell
65 // The location of the cell in the index
66 // array can be found by calling xyz2ci
67 int* nra; // The number of entries in a cell
68 int icg0; // The start of the i-cg range
69 int icg1; // The end of the i-cg range
72 int* a; // The grid of cgs
73 int nr_alloc; // Allocation size of cell_index and a
74 real* dcx2; // Squared distance from atom to j-cell
75 real* dcy2; // Squared distance from atom to j-cell
76 real* dcz2; // Squared distance from atom to j-cell
77 int dc_nalloc; // Allocation size of dcx2, dyc2, dcz2
80 /*! \brief Used when estimating the interaction density.
82 * GRID_STDDEV_FAC * stddev estimates the interaction density. The
83 * value sqrt(3) == 1.73205080757 gives a uniform load for a
84 * rectangular 3D block of charge groups. For a sphere, it is not a
85 * bad approximation for 4x1x1 up to 4x2x2.
87 * \todo It would be nicer to use sqrt(3) here, when all code that
88 * includes this file is in C++, which will let us cope with the
89 * std::sqrt<T> on Windows. */
90 static const real GRID_STDDEV_FAC = 1.73205080757;
92 /*! \brief The extent of the neighborsearch grid is a bit larger than sqrt(3)
93 * to account for less dense regions at the edges of the system.
95 static const real NSGRID_STDDEV_FAC = 2.0;
97 #define NSGRID_SIGNAL_MOVED_FAC 4
98 /* A cell index of NSGRID_SIGNAL_MOVED_FAC*ncells signals
99 * that a charge group moved to another DD domain.
102 t_grid* init_grid(FILE* fplog, t_forcerec* fr);
104 void done_grid(t_grid* grid);
106 void get_nsgrid_boundaries(int nboundeddim,
108 struct gmx_domdec_t* dd,
117 /* Return the ns grid boundaries grid_x0 and grid_x1
118 * and the estimate for the grid density.
119 * For non-bounded dimensions the boundaries are determined
120 * from the average and std.dev. of cgcm.
121 * The are determined from box, unless gr0!=NULL or gr1!=NULL,
122 * then they are taken from gr0 or gr1.
123 * With dd and unbounded dimensions, the proper grid borders for cells
124 * on the edges are determined from cgcm.
127 void grid_first(FILE* log,
129 struct gmx_domdec_t* dd,
130 const gmx_ddbox_t* ddbox,
137 void fill_grid(struct gmx_domdec_zones_t* dd_zones, t_grid* grid, int ncg_tot, int cg0, int cg1, rvec cg_cm[]);
138 /* Allocates space on the grid for ncg_tot cg's.
139 * Fills the grid with cg's from cg0 to cg1.
140 * When cg0 is -1, contiues filling from grid->nr to cg1.
143 void calc_elemnr(t_grid* grid, int cg0, int cg1, int ncg);
145 void calc_ptrs(t_grid* grid);
147 void grid_last(t_grid* grid, int cg0, int cg1, int ncg);
149 int xyz2ci_(int nry, int nrz, int x, int y, int z);
150 #define xyz2ci(nry, nrz, x, y, z) ((nry) * (nrz) * (x) + (nrz) * (y) + (z))
151 /* Return the cell index */
153 void ci2xyz(t_grid* grid, int i, int* x, int* y, int* z);
155 void check_grid(t_grid* grid);
157 void print_grid(FILE* log, t_grid* grid);