src/gromacs/ewald/pme.h

   1 /*
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  37 /*! \libinternal \file
  38  *
  39  * \brief This file contains function declarations necessary for
  40  * computing energies and forces for the PME long-ranged part (Coulomb
  41  * and LJ).
  42  *
  43  * \author Berk Hess <hess@kth.se>
  44  * \inlibraryapi
  45  * \ingroup module_ewald
  46  */
  47
  48 #ifndef GMX_EWALD_PME_H
  49 #define GMX_EWALD_PME_H
  50
  51 #include <stdio.h>
  52
  53 #include "gromacs/gmxlib/nrnb.h"
  54 #include "gromacs/math/vectypes.h"
  55 #include "gromacs/mdtypes/forcerec.h"
  56 #include "gromacs/mdtypes/interaction_const.h"
  57 #include "gromacs/timing/wallcycle.h"
  58 #include "gromacs/timing/walltime_accounting.h"
  59 #include "gromacs/utility/basedefinitions.h"
  60 #include "gromacs/utility/real.h"
  61
  62 struct t_commrec;
  63 struct t_inputrec;
  64
  65 enum {
  66     GMX_SUM_GRID_FORWARD, GMX_SUM_GRID_BACKWARD
  67 };
  68
  69 /*! \brief Return the smallest allowed PME grid size for \p pmeOrder */
  70 int minimalPmeGridSize(int pmeOrder);
  71
  72 /*! \brief Initialize \p pmedata
  73  *
  74  * \returns  0 indicates all well, non zero is an error code.
  75  * \throws   gmx::InconsistentInputError if input grid sizes/PME order are inconsistent.
  76  */
  77 int gmx_pme_init(struct gmx_pme_t **pmedata, struct t_commrec *cr,
  78                  int nnodes_major, int nnodes_minor,
  79                  const t_inputrec *ir, int homenr,
  80                  gmx_bool bFreeEnergy_q, gmx_bool bFreeEnergy_lj,
  81                  gmx_bool bReproducible,
  82                  real ewaldcoeff_q, real ewaldcoeff_lj,
  83                  int nthread);
  84
  85 /*! \brief Destroys the PME data structure.*/
  86 void gmx_pme_destroy(gmx_pme_t *pme);
  87
  88 //@{
  89 /*! \brief Flag values that control what gmx_pme_do() will calculate
  90  *
  91  * These can be combined with bitwise-OR if more than one thing is required.
  92  */
  93 #define GMX_PME_SPREAD        (1<<0)
  94 #define GMX_PME_SOLVE         (1<<1)
  95 #define GMX_PME_CALC_F        (1<<2)
  96 #define GMX_PME_CALC_ENER_VIR (1<<3)
  97 /* This forces the grid to be backtransformed even without GMX_PME_CALC_F */
  98 #define GMX_PME_CALC_POT      (1<<4)
  99
 100 #define GMX_PME_DO_ALL_F  (GMX_PME_SPREAD | GMX_PME_SOLVE | GMX_PME_CALC_F)
 101 //@}
 102
 103 /*! \brief Do a PME calculation for the long range electrostatics and/or LJ.
 104  *
 105  * The meaning of \p flags is defined above, and determines which
 106  * parts of the calculation are performed.
 107  *
 108  * \return 0 indicates all well, non zero is an error code.
 109  */
 110 int gmx_pme_do(struct gmx_pme_t *pme,
 111                int start,       int homenr,
 112                rvec x[],        rvec f[],
 113                real chargeA[],  real chargeB[],
 114                real c6A[],      real c6B[],
 115                real sigmaA[],   real sigmaB[],
 116                matrix box,      t_commrec *cr,
 117                int  maxshift_x, int maxshift_y,
 118                t_nrnb *nrnb,    gmx_wallcycle_t wcycle,
 119                matrix vir_q,    matrix vir_lj,
 120                real *energy_q,  real *energy_lj,
 121                real lambda_q,   real lambda_lj,
 122                real *dvdlambda_q, real *dvdlambda_lj,
 123                int flags);
 124
 125 /*! \brief Called on the nodes that do PME exclusively (as slaves) */
 126 int gmx_pmeonly(struct gmx_pme_t *pme,
 127                 struct t_commrec *cr,     t_nrnb *mynrnb,
 128                 gmx_wallcycle_t wcycle,
 129                 gmx_walltime_accounting_t walltime_accounting,
 130                 real ewaldcoeff_q, real ewaldcoeff_lj,
 131                 t_inputrec *ir);
 132
 133 /*! \brief Calculate the PME grid energy V for n charges.
 134  *
 135  * The potential (found in \p pme) must have been found already with a
 136  * call to gmx_pme_do() with at least GMX_PME_SPREAD and GMX_PME_SOLVE
 137  * specified. Note that the charges are not spread on the grid in the
 138  * pme struct. Currently does not work in parallel or with free
 139  * energy.
 140  */
 141 void gmx_pme_calc_energy(struct gmx_pme_t *pme, int n, rvec *x, real *q, real *V);
 142
 143 /*! \brief Send the charges and maxshift to out PME-only node. */
 144 void gmx_pme_send_parameters(struct t_commrec *cr,
 145                              const interaction_const_t *ic,
 146                              gmx_bool bFreeEnergy_q, gmx_bool bFreeEnergy_lj,
 147                              real *chargeA, real *chargeB,
 148                              real *sqrt_c6A, real *sqrt_c6B,
 149                              real *sigmaA, real *sigmaB,
 150                              int maxshift_x, int maxshift_y);
 151
 152 /*! \brief Send the coordinates to our PME-only node and request a PME calculation */
 153 void gmx_pme_send_coordinates(struct t_commrec *cr, matrix box, rvec *x,
 154                               real lambda_q, real lambda_lj,
 155                               gmx_bool bEnerVir,
 156                               gmx_int64_t step);
 157
 158 /*! \brief Tell our PME-only node to finish */
 159 void gmx_pme_send_finish(struct t_commrec *cr);
 160
 161 /*! \brief Tell our PME-only node to reset all cycle and flop counters */
 162 void gmx_pme_send_resetcounters(struct t_commrec *cr, gmx_int64_t step);
 163
 164 /*! \brief PP nodes receive the long range forces from the PME nodes */
 165 void gmx_pme_receive_f(struct t_commrec *cr,
 166                        rvec f[], matrix vir_q, real *energy_q,
 167                        matrix vir_lj, real *energy_lj,
 168                        real *dvdlambda_q, real *dvdlambda_lj,
 169                        float *pme_cycles);
 170
 171 #endif