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33 * GROningen Mixture of Alchemy and Childrens' Stories
55 #include "thread_mpi.h"
58 #define p2(x) ((x)*(x))
59 #define p3(x) ((x)*(x)*(x))
60 #define p4(x) ((x)*(x)*(x)*(x))
62 static real A,A_3,B,B_4,C,c1,c2,c3,c4,c5,c6,One_4pi,FourPi_V,Vol,N0;
64 static tMPI_Thread_mutex_t shift_mutex=TMPI_THREAD_MUTEX_INITIALIZER;
68 void set_shift_consts(FILE *log,real r1,real rc,rvec box,t_forcerec *fr)
71 /* at the very least we shouldn't allow multiple threads to set these
73 tMPI_Thread_mutex_lock(&shift_mutex);
75 /* A, B and C are recalculated in tables.c */
77 A = (2*r1-5*rc)/(p3(rc)*p2(rc-r1));
78 B = (4*rc-2*r1)/(p3(rc)*p3(rc-r1));
79 /*C = (10*rc*rc-5*rc*r1+r1*r1)/(6*rc*rc); Hermans Eq. not correct */
82 gmx_fatal(FARGS,"r1 (%f) >= rc (%f) in %s, line %d",
83 r1,rc,__FILE__,__LINE__);
87 C = 1/rc-A_3*p3(rc-r1)-B_4*p4(rc-r1);
88 N0 = 2.0*M_PI*p3(rc)*p3(rc-r1);
90 Vol =(box[XX]*box[YY]*box[ZZ]);
91 FourPi_V=4.0*M_PI/Vol;
94 fprintf(debug,"Constants for short-range and fourier stuff:\n"
95 "r1 = %10.3f, rc = %10.3f\n"
96 "A = %10.3e, B = %10.3e, C = %10.3e, FourPi_V = %10.3e\n",
97 r1,rc,A,B,C,FourPi_V);
100 /* Constants derived by Mathematica */
101 c1 = -40*rc*rc + 50*rc*r1 - 16*r1*r1;
103 c3 = -10*rc*rc*rc + 20*rc*rc*r1 - 13*rc*r1*r1 + 3*r1*r1*r1;
104 c4 = -20*rc*rc + 40*rc*r1 - 14*r1*r1;
106 c6 = -5*rc*rc*r1 + 7*rc*r1*r1 - 2*r1*r1*r1;
109 fprintf(debug,"c1 = %10.3e, c2 = %10.3e, c3 = %10.3e\n"
110 "c4 = %10.3e, c5 = %10.3e, c6 = %10.3e, N0 = %10.3e\n",
111 c1,c2,c3,c4,c5,c6,N0);
114 One_4pi = 1.0/(4.0*M_PI);
115 #ifdef GMX_THREAD_MPI
116 tMPI_Thread_mutex_unlock(&shift_mutex);