1 // clang-format off
2 /* ----------------------------------------------------------------------
3 LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
4 https://www.lammps.org/, Sandia National Laboratories
5 Steve Plimpton, sjplimp@sandia.gov
6
7 Copyright (2003) Sandia Corporation. Under the terms of Contract
8 DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
9 certain rights in this software. This software is distributed under
10 the GNU General Public License.
11
12 See the README file in the top-level LAMMPS directory.
13 ------------------------------------------------------------------------- */
14
15 /* ----------------------------------------------------------------------
16 Contributing author:
17 Rodolfo Paula Leite (Unicamp/Brazil) - pl.rodolfo@gmail.com
18 Maurice de Koning (Unicamp/Brazil) - dekoning@ifi.unicamp.br
19 ------------------------------------------------------------------------- */
20
21 #include "pair_ufm_opt.h"
22
23 #include <cmath>
24 #include "atom.h"
25 #include "force.h"
26 #include "neigh_list.h"
27
28 using namespace LAMMPS_NS;
29
30 /* ---------------------------------------------------------------------- */
31
PairUFMOpt(LAMMPS * lmp)32 PairUFMOpt::PairUFMOpt(LAMMPS *lmp) : PairUFM(lmp) {}
33
34 /* ---------------------------------------------------------------------- */
35
compute(int eflag,int vflag)36 void PairUFMOpt::compute(int eflag, int vflag)
37 {
38 ev_init(eflag,vflag);
39
40 if (evflag) {
41 if (eflag) {
42 if (force->newton_pair) return eval<1,1,1>();
43 else return eval<1,1,0>();
44 } else {
45 if (force->newton_pair) return eval<1,0,1>();
46 else return eval<1,0,0>();
47 }
48 } else {
49 if (force->newton_pair) return eval<0,0,1>();
50 else return eval<0,0,0>();
51 }
52 }
53
54 /* ---------------------------------------------------------------------- */
55
56 template < int EVFLAG, int EFLAG, int NEWTON_PAIR >
eval()57 void PairUFMOpt::eval()
58 {
59 typedef struct { double x,y,z; } vec3_t;
60
61 typedef struct {
62 double cutsq,uf1,uf2,uf3,scale,offset;
63 double _pad[2];
64 } fast_alpha_t;
65
66 int i,j,ii,jj,inum,jnum,itype,jtype,sbindex;
67 double factor_lj;
68 double evdwl = 0.0;
69
70 double** _noalias x = atom->x;
71 double** _noalias f = atom->f;
72 int* _noalias type = atom->type;
73 int nlocal = atom->nlocal;
74 double* _noalias special_lj = force->special_lj;
75
76 inum = list->inum;
77 int* _noalias ilist = list->ilist;
78 int** _noalias firstneigh = list->firstneigh;
79 int* _noalias numneigh = list->numneigh;
80
81 vec3_t* _noalias xx = (vec3_t*)x[0];
82 vec3_t* _noalias ff = (vec3_t*)f[0];
83
84 int ntypes = atom->ntypes;
85 int ntypes2 = ntypes*ntypes;
86
87 fast_alpha_t* _noalias fast_alpha =
88 (fast_alpha_t*) malloc(ntypes2*sizeof(fast_alpha_t));
89 for (i = 0; i < ntypes; i++) for (j = 0; j < ntypes; j++) {
90 fast_alpha_t& a = fast_alpha[i*ntypes+j];
91 a.cutsq = cutsq[i+1][j+1];
92 a.uf1 = uf1[i+1][j+1];
93 a.uf2 = uf2[i+1][j+1];
94 a.uf3 = uf3[i+1][j+1];
95 a.scale = scale[i+1][j+1];
96 a.offset = offset[i+1][j+1];
97 }
98 fast_alpha_t* _noalias tabsix = fast_alpha;
99
100 // loop over neighbors of my atoms
101
102 for (ii = 0; ii < inum; ii++) {
103 i = ilist[ii];
104 double xtmp = xx[i].x;
105 double ytmp = xx[i].y;
106 double ztmp = xx[i].z;
107 itype = type[i] - 1;
108 int* _noalias jlist = firstneigh[i];
109 jnum = numneigh[i];
110
111 double tmpfx = 0.0;
112 double tmpfy = 0.0;
113 double tmpfz = 0.0;
114
115 fast_alpha_t* _noalias tabsixi = (fast_alpha_t*)&tabsix[itype*ntypes];
116
117 for (jj = 0; jj < jnum; jj++) {
118 j = jlist[jj];
119 sbindex = sbmask(j);
120
121 if (sbindex == 0) {
122 double delx = xtmp - xx[j].x;
123 double dely = ytmp - xx[j].y;
124 double delz = ztmp - xx[j].z;
125 double rsq = delx*delx + dely*dely + delz*delz;
126
127 jtype = type[j] - 1;
128
129 fast_alpha_t& a = tabsixi[jtype];
130
131 if (rsq < a.cutsq) {
132 double expuf = exp(- rsq * a.uf2);
133 double fpair = a.scale * a.uf1 * expuf / (1.0 - expuf);
134
135 tmpfx += delx*fpair;
136 tmpfy += dely*fpair;
137 tmpfz += delz*fpair;
138 if (NEWTON_PAIR || j < nlocal) {
139 ff[j].x -= delx*fpair;
140 ff[j].y -= dely*fpair;
141 ff[j].z -= delz*fpair;
142 }
143
144 if (EFLAG) evdwl = - a.uf3 * log(1.0 - expuf) - a.offset;
145
146 if (EVFLAG)
147 ev_tally(i,j,nlocal,NEWTON_PAIR,
148 evdwl,0.0,fpair,delx,dely,delz);
149 }
150
151 } else {
152 factor_lj = special_lj[sbindex];
153 j &= NEIGHMASK;
154
155 double delx = xtmp - xx[j].x;
156 double dely = ytmp - xx[j].y;
157 double delz = ztmp - xx[j].z;
158 double rsq = delx*delx + dely*dely + delz*delz;
159
160 int jtype1 = type[j];
161 jtype = jtype1 - 1;
162
163 fast_alpha_t& a = tabsixi[jtype];
164 if (rsq < a.cutsq) {
165 fast_alpha_t& a = tabsixi[jtype];
166 double expuf = exp(- rsq * a.uf2);
167 double fpair = a.scale * factor_lj * a.uf1 * expuf / (1.0 - expuf);
168
169 tmpfx += delx*fpair;
170 tmpfy += dely*fpair;
171 tmpfz += delz*fpair;
172 if (NEWTON_PAIR || j < nlocal) {
173 ff[j].x -= delx*fpair;
174 ff[j].y -= dely*fpair;
175 ff[j].z -= delz*fpair;
176 }
177
178 if (EFLAG) {
179 evdwl = - a.uf3 * log(1.0 - expuf) - a.offset;
180 evdwl *= factor_lj;
181 }
182
183 if (EVFLAG) ev_tally(i,j,nlocal,NEWTON_PAIR,
184 evdwl,0.0,fpair,delx,dely,delz);
185 }
186 }
187 }
188
189 ff[i].x += tmpfx;
190 ff[i].y += tmpfy;
191 ff[i].z += tmpfz;
192 }
193
194 free(fast_alpha); fast_alpha = 0;
195
196 if (vflag_fdotr) virial_fdotr_compute();
197 }
198