src/gromacs/legacyheaders/types/interaction_const.h

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  35
  36 #ifndef _INTERACTION_CONST_
  37 #define _INTERACTION_CONST_
  38
  39 #ifdef __cplusplus
  40 extern "C" {
  41 #endif
  42
  43 /* Used with force switching or a constant potential shift:
  44  * rsw       = max(r - r_switch, 0)
  45  * force/p   = r^-(p+1) + c2*rsw^2 + c3*rsw^3
  46  * potential = r^-p + c2/3*rsw^3 + c3/4*rsw^4 + cpot
  47  * With a constant potential shift c2 and c3 are both 0.
  48  */
  49 typedef struct {
  50     real c2;
  51     real c3;
  52     real cpot;
  53 } shift_consts_t;
  54
  55 /* Used with potential switching:
  56  * rsw        = max(r - r_switch, 0)
  57  * sw         = 1 + c3*rsw^3 + c4*rsw^4 + c5*rsw^5
  58  * dsw        = 3*c3*rsw^2 + 4*c4*rsw^3 + 5*c5*rsw^4
  59  * force      = force*dsw - potential*sw
  60  * potential *= sw
  61  */
  62 typedef struct {
  63     real c3;
  64     real c4;
  65     real c5;
  66 } switch_consts_t;
  67
  68 typedef struct {
  69     /* VdW */
  70     int             vdwtype;
  71     int             vdw_modifier;
  72     real            rvdw;
  73     real            rvdw_switch;
  74     shift_consts_t  dispersion_shift;
  75     shift_consts_t  repulsion_shift;
  76     switch_consts_t vdw_switch;
  77     /* TODO: remove this variable, used for not modyfing the group kernels,
  78      * it is equal to -dispersion_shift->cpot
  79      */
  80     real sh_invrc6;
  81
  82     /* type of electrostatics (defined in enums.h) */
  83     int  eeltype;
  84     int  coulomb_modifier;
  85
  86     /* Coulomb */
  87     real rcoulomb;
  88
  89     /* Cut-off */
  90     real rlist;
  91     real rlistlong;
  92
  93     /* PME/Ewald */
  94     real ewaldcoeff_q;
  95     real ewaldcoeff_lj;
  96     int  ljpme_comb_rule; /* LJ combination rule for the LJ PME mesh part */
  97     real sh_ewald;        /* -sh_ewald is added to the direct space potential */
  98     real sh_lj_ewald;     /* sh_lj_ewald is added to the correction potential */
  99
 100     /* Dielectric constant resp. multiplication factor for charges */
 101     real epsilon_r;
 102     real epsfac;
 103
 104     /* Constants for reaction-field or plain cut-off */
 105     real epsilon_rf;
 106     real k_rf;
 107     real c_rf;
 108
 109     /* Force/energy interpolation tables, linear in force, quadratic in V */
 110     real  tabq_scale;
 111     int   tabq_size;
 112     /* Coulomb force table, size of array is tabq_size (when used) */
 113     real *tabq_coul_F;
 114     /* Coulomb energy table, size of array is tabq_size (when used) */
 115     real *tabq_coul_V;
 116     /* Coulomb force+energy table, size of array is tabq_size*4,
 117        entry quadruplets are: F[i], F[i+1]-F[i], V[i], 0,
 118        this is used with single precision x86 SIMD for aligned loads */
 119     real *tabq_coul_FDV0;
 120 } interaction_const_t;
 121
 122 #ifdef __cplusplus
 123 }
 124 #endif
 125
 126 #endif /* _INTERACTION_CONST_ */