1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
#include <libint2.h>
#include <math.h>
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
Libint_t erieval;
double* F;
#ifndef M_PI
# define M_PI 3.1415926535897932384626433832795
#endif
/* computes F[0] .. F[max_m] */
extern void calc_f(double* F, double T, unsigned int max_m);
#if defined(LIBINT2_SUPPORT_ERI) && LIBINT2_MAX_AM_eri >= 1
/** This function evaluates ERI over 4 primitive Gaussian shells.
See tests/eri/test.cc for an example of how to deal with
contracted Gaussians.
For simplicity, many details are omitted here, e.g. normalization.
*/
void
_compute_eri(Libint_t* erieval,
unsigned int am1, double alpha1, double* A,
unsigned int am2, double alpha2, double* B,
unsigned int am3, double alpha3, double* C,
unsigned int am4, double alpha4, double* D
)
{
/* I will assume that libint2_static_init() and libint2_init_eri(&erieval,max_am,0) had been called elsewhere! */
double gammap, Px, Py, Pz, PAx, PAy, PAz, PBx, PBy, PBz, AB2;
double gammaq, Qx, Qy, Qz, QCx, QCy, QCz, QDx, QDy, QDz, CD2;
double gammapq, PQx, PQy, PQz, PQ2, Wx, Wy, Wz;
double K1, K2, pfac;
unsigned int am;
double* eri_shell_set;
/*
Compute requisite data -- many of these quantities would be precomputed
for all nonnegligible shell pairs somewhere else
*/
gammap = alpha1 + alpha2;
Px = (alpha1*A[0] + alpha2*B[0])/gammap;
Py = (alpha1*A[1] + alpha2*B[1])/gammap;
Pz = (alpha1*A[2] + alpha2*B[2])/gammap;
PAx = Px - A[0];
PAy = Py - A[1];
PAz = Pz - A[2];
PBx = Px - B[0];
PBy = Py - B[1];
PBz = Pz - B[2];
AB2 = (A[0]-B[0])*(A[0]-B[0])
+ (A[1]-B[1])*(A[1]-B[1])
+ (A[2]-B[2])*(A[2]-B[2]);
erieval->PA_x[0] = PAx;
erieval->PA_y[0] = PAy;
erieval->PA_z[0] = PAz;
erieval->AB_x[0] = A[0] - B[0];
erieval->AB_y[0] = A[1] - B[1];
erieval->AB_z[0] = A[2] - B[2];
erieval->oo2z[0] = 0.5/gammap;
gammaq = alpha3 + alpha4;
gammapq = gammap*gammaq/(gammap+gammaq);
Qx = (alpha3*C[0] + alpha4*D[0])/gammaq;
Qy = (alpha3*C[1] + alpha4*D[1])/gammaq;
Qz = (alpha3*C[2] + alpha4*D[2])/gammaq;
QCx = Qx - C[0];
QCy = Qy - C[1];
QCz = Qz - C[2];
QDx = Qx - D[0];
QDy = Qy - D[1];
QDz = Qz - D[2];
CD2 = (C[0]-D[0])*(C[0]-D[0])
+ (C[1]-D[1])*(C[1]-D[1])
+ (C[2]-D[2])*(C[2]-D[2]);
erieval->QC_x[0] = QCx;
erieval->QC_y[0] = QCy;
erieval->QC_z[0] = QCz;
erieval->CD_x[0] = C[0] - D[0];
erieval->CD_y[0] = C[1] - D[1];
erieval->CD_z[0] = C[2] - D[2];
erieval->oo2e[0] = 0.5/gammaq;
PQx = Px - Qx;
PQy = Py - Qy;
PQz = Pz - Qz;
PQ2 = PQx*PQx + PQy*PQy + PQz*PQz;
Wx = (gammap*Px + gammaq*Qx)/(gammap+gammaq);
Wy = (gammap*Py + gammaq*Qy)/(gammap+gammaq);
Wz = (gammap*Pz + gammaq*Qz)/(gammap+gammaq);
erieval->WP_x[0] = Wx - Px;
erieval->WP_y[0] = Wy - Py;
erieval->WP_z[0] = Wz - Pz;
erieval->WQ_x[0] = Wx - Qx;
erieval->WQ_y[0] = Wy - Qy;
erieval->WQ_z[0] = Wz - Qz;
erieval->oo2ze[0] = 0.5/(gammap+gammaq);
erieval->roz[0] = gammapq/gammap;
erieval->roe[0] = gammapq/gammaq;
K1 = exp(-alpha1*alpha2*AB2/gammap);
K2 = exp(-alpha3*alpha4*CD2/gammaq);
pfac = 2*pow(M_PI,2.5)*K1*K2/(gammap*gammaq*sqrt(gammap+gammaq));
/*
evaluate Boys function F_m for all m in [0,am]
*/
am = am1 + am2 + am3 + am4;
calc_f(F, PQ2*gammapq, am);
/* (00|00)^m = pfac * F_m */
assert(am <= 4);
erieval->LIBINT_T_SS_EREP_SS(0)[0] = pfac*F[0];
erieval->LIBINT_T_SS_EREP_SS(1)[0] = pfac*F[1];
erieval->LIBINT_T_SS_EREP_SS(2)[0] = pfac*F[2];
erieval->LIBINT_T_SS_EREP_SS(3)[0] = pfac*F[3];
erieval->LIBINT_T_SS_EREP_SS(4)[0] = pfac*F[4];
/* compute ERIs */
libint2_build_eri[am1][am2][am3][am4](erieval);
}
void init_c_api(unsigned int max_am) {
libint2_init_eri(&erieval, max_am, 0);
F = malloc(sizeof(double)*(4*max_am+1));
#if LIBINT_CONTRACTED_INTS
/* if have support for contracted integrals, set the contraction length to 1 */
erieval.contrdepth = 1;
#endif
}
double*
compute_eri(unsigned int am1, double alpha1, double* A,
unsigned int am2, double alpha2, double* B,
unsigned int am3, double alpha3, double* C,
unsigned int am4, double alpha4, double* D) {
_compute_eri(&erieval, am1, alpha1, A, am2, alpha2, B, am3, alpha3, C, am4, alpha4, D);
return erieval.targets[0];
}
void finalize_c_api() {
free(F);
libint2_cleanup_eri(&erieval);
}
#endif
|
