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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
|
c Extern "C" declaration has the form:
c
c void meam_dens_final_(int *, int *, int *, int *, int *, double *, double *,
c int *, int *, int *,
c double *, double *, double *, double *, double *, double *,
c double *, double *, double *, double *, double *, double *,
c double *, double *, double *, double *, double *, int *);
c
c Call from pair_meam.cpp has the form:
c
c meam_dens_final_(&nlocal,&nmax,&eflag_either,&eflag_global,&eflag_atom,
c &eng_vdwl,eatom,ntype,type,fmap,
c &arho1[0][0],&arho2[0][0],arho2b,&arho3[0][0],
c &arho3b[0][0],&t_ave[0][0],&tsq_ave[0][0],gamma,dgamma1,
c dgamma2,dgamma3,rho,rho0,rho1,rho2,rho3,frhop,&errorflag);
c
subroutine meam_dens_final(nlocal, nmax,
$ eflag_either, eflag_global, eflag_atom, eng_vdwl, eatom,
$ ntype, type, fmap,
$ Arho1, Arho2, Arho2b, Arho3, Arho3b, t_ave, tsq_ave,
$ Gamma, dGamma1, dGamma2, dGamma3,
$ rho, rho0, rho1, rho2, rho3, fp, errorflag)
use meam_data
implicit none
integer nlocal, nmax, eflag_either, eflag_global, eflag_atom
integer ntype, type, fmap
real*8 eng_vdwl, eatom, Arho1, Arho2
real*8 Arho2b, Arho3, Arho3b
real*8 t_ave, tsq_ave
real*8 Gamma, dGamma1, dGamma2, dGamma3
real*8 rho, rho0, rho1, rho2, rho3
real*8 fp
integer errorflag
dimension eatom(nmax)
dimension type(nmax), fmap(ntype)
dimension Arho1(3,nmax), Arho2(6,nmax), Arho2b(nmax)
dimension Arho3(10,nmax), Arho3b(3,nmax), t_ave(3,nmax)
dimension tsq_ave(3,nmax)
dimension Gamma(nmax), dGamma1(nmax), dGamma2(nmax)
dimension dGamma3(nmax), rho(nmax), rho0(nmax)
dimension rho1(nmax), rho2(nmax), rho3(nmax)
dimension fp(nmax)
integer i, elti
integer m
real*8 rhob, G, dG, Gbar, dGbar, gam, shp(3), shpi(3), Z
real*8 B, denom, rho_bkgd
c Complete the calculation of density
do i = 1,nlocal
elti = fmap(type(i))
if (elti.gt.0) then
rho1(i) = 0.d0
rho2(i) = -1.d0/3.d0*Arho2b(i)*Arho2b(i)
rho3(i) = 0.d0
do m = 1,3
rho1(i) = rho1(i) + Arho1(m,i)*Arho1(m,i)
rho3(i) = rho3(i) - 3.d0/5.d0*Arho3b(m,i)*Arho3b(m,i)
enddo
do m = 1,6
rho2(i) = rho2(i) + v2D(m)*Arho2(m,i)*Arho2(m,i)
enddo
do m = 1,10
rho3(i) = rho3(i) + v3D(m)*Arho3(m,i)*Arho3(m,i)
enddo
if( rho0(i) .gt. 0.0 ) then
if (ialloy.eq.1) then
if (tsq_ave(1,i) .ne. 0.0d0) then
t_ave(1,i) = t_ave(1,i)/tsq_ave(1,i)
else
t_ave(1,i) = 0.0d0
endif
if (tsq_ave(2,i) .ne. 0.0d0) then
t_ave(2,i) = t_ave(2,i)/tsq_ave(2,i)
else
t_ave(2,i) = 0.0d0
endif
if (tsq_ave(3,i) .ne. 0.0d0) then
t_ave(3,i) = t_ave(3,i)/tsq_ave(3,i)
else
t_ave(3,i) = 0.0d0
endif
else if (ialloy.eq.2) then
t_ave(1,i) = t1_meam(elti)
t_ave(2,i) = t2_meam(elti)
t_ave(3,i) = t3_meam(elti)
else
t_ave(1,i) = t_ave(1,i)/rho0(i)
t_ave(2,i) = t_ave(2,i)/rho0(i)
t_ave(3,i) = t_ave(3,i)/rho0(i)
endif
endif
Gamma(i) = t_ave(1,i)*rho1(i)
$ + t_ave(2,i)*rho2(i) + t_ave(3,i)*rho3(i)
if( rho0(i) .gt. 0.0 ) then
Gamma(i) = Gamma(i)/(rho0(i)*rho0(i))
end if
Z = Z_meam(elti)
call G_gam(Gamma(i),ibar_meam(elti),
$ gsmooth_factor,G,errorflag)
if (errorflag.ne.0) return
call get_shpfcn(shp,lattce_meam(elti,elti))
if (ibar_meam(elti).le.0) then
Gbar = 1.d0
dGbar = 0.d0
else
if (mix_ref_t.eq.1) then
gam = (t_ave(1,i)*shp(1)+t_ave(2,i)*shp(2)
$ +t_ave(3,i)*shp(3))/(Z*Z)
else
gam = (t1_meam(elti)*shp(1)+t2_meam(elti)*shp(2)
$ +t3_meam(elti)*shp(3))/(Z*Z)
endif
call G_gam(gam,ibar_meam(elti),gsmooth_factor,
$ Gbar,errorflag)
endif
rho(i) = rho0(i) * G
if (mix_ref_t.eq.1) then
if (ibar_meam(elti).le.0) then
Gbar = 1.d0
dGbar = 0.d0
else
gam = (t_ave(1,i)*shp(1)+t_ave(2,i)*shp(2)
$ +t_ave(3,i)*shp(3))/(Z*Z)
call dG_gam(gam,ibar_meam(elti),gsmooth_factor,
$ Gbar,dGbar)
endif
rho_bkgd = rho0_meam(elti)*Z*Gbar
else
if (bkgd_dyn.eq.1) then
rho_bkgd = rho0_meam(elti)*Z
else
rho_bkgd = rho_ref_meam(elti)
endif
endif
rhob = rho(i)/rho_bkgd
denom = 1.d0/rho_bkgd
call dG_gam(Gamma(i),ibar_meam(elti),gsmooth_factor,G,dG)
dGamma1(i) = (G - 2*dG*Gamma(i))*denom
if( rho0(i) .ne. 0.d0 ) then
dGamma2(i) = (dG/rho0(i))*denom
else
dGamma2(i) = 0.d0
end if
c dGamma3 is nonzero only if we are using the "mixed" rule for
c computing t in the reference system (which is not correct, but
c included for backward compatibility
if (mix_ref_t.eq.1) then
dGamma3(i) = rho0(i)*G*dGbar/(Gbar*Z*Z)*denom
else
dGamma3(i) = 0.0
endif
B = A_meam(elti)*Ec_meam(elti,elti)
if( rhob .ne. 0.d0 ) then
if (emb_lin_neg.eq.1 .and. rhob.le.0) then
fp(i) = -B
else
fp(i) = B*(log(rhob)+1.d0)
endif
if (eflag_either.ne.0) then
if (eflag_global.ne.0) then
if (emb_lin_neg.eq.1 .and. rhob.le.0) then
eng_vdwl = eng_vdwl - B*rhob
else
eng_vdwl = eng_vdwl + B*rhob*log(rhob)
endif
endif
if (eflag_atom.ne.0) then
if (emb_lin_neg.eq.1 .and. rhob.le.0) then
eatom(i) = eatom(i) - B*rhob
else
eatom(i) = eatom(i) + B*rhob*log(rhob)
endif
endif
endif
else
if (emb_lin_neg.eq.1) then
fp(i) = -B
else
fp(i) = B
endif
endif
endif
enddo
return
end
cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
subroutine G_gam(Gamma,ibar,gsmooth_factor,G,errorflag)
c Compute G(Gamma) based on selection flag ibar:
c 0 => G = sqrt(1+Gamma)
c 1 => G = exp(Gamma/2)
c 2 => not implemented
c 3 => G = 2/(1+exp(-Gamma))
c 4 => G = sqrt(1+Gamma)
c -5 => G = +-sqrt(abs(1+Gamma))
use meam_data , only: fm_exp
implicit none
real*8 Gamma,G
real*8 gsmooth_factor, gsmooth_switchpoint
integer ibar, errorflag
if (ibar.eq.0.or.ibar.eq.4) then
gsmooth_switchpoint = -gsmooth_factor / (gsmooth_factor+1)
if (Gamma.lt.gsmooth_switchpoint) then
c e.g. gsmooth_factor is 99, then:
c gsmooth_switchpoint = -0.99
c G = 0.01*(-0.99/Gamma)**99
G = 1/(gsmooth_factor+1)
$ *(gsmooth_switchpoint/Gamma)**gsmooth_factor
G = sqrt(G)
else
G = sqrt(1.d0+Gamma)
endif
else if (ibar.eq.1) then
G = fm_exp(Gamma/2.d0)
else if (ibar.eq.3) then
G = 2.d0/(1.d0+exp(-Gamma))
else if (ibar.eq.-5) then
if ((1.d0+Gamma).ge.0) then
G = sqrt(1.d0+Gamma)
else
G = -sqrt(-1.d0-Gamma)
endif
else
errorflag = 1
endif
return
end
cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
subroutine dG_gam(Gamma,ibar,gsmooth_factor,G,dG)
c Compute G(Gamma) and dG(gamma) based on selection flag ibar:
c 0 => G = sqrt(1+Gamma)
c 1 => G = fm_exp(Gamma/2)
c 2 => not implemented
c 3 => G = 2/(1+fm_exp(-Gamma))
c 4 => G = sqrt(1+Gamma)
c -5 => G = +-sqrt(abs(1+Gamma))
use meam_data , only: fm_exp
real*8 Gamma,G,dG
real*8 gsmooth_factor, gsmooth_switchpoint
integer ibar
if (ibar.eq.0.or.ibar.eq.4) then
gsmooth_switchpoint = -gsmooth_factor / (gsmooth_factor+1)
if (Gamma.lt.gsmooth_switchpoint) then
c e.g. gsmooth_factor is 99, then:
c gsmooth_switchpoint = -0.99
c G = 0.01*(-0.99/Gamma)**99
G = 1/(gsmooth_factor+1)
$ *(gsmooth_switchpoint/Gamma)**gsmooth_factor
G = sqrt(G)
dG = -gsmooth_factor*G/(2.0*Gamma)
else
G = sqrt(1.d0+Gamma)
dG = 1.d0/(2.d0*G)
endif
else if (ibar.eq.1) then
G = fm_exp(Gamma/2.d0)
dG = G/2.d0
else if (ibar.eq.3) then
G = 2.d0/(1.d0+fm_exp(-Gamma))
dG = G*(2.d0-G)/2
else if (ibar.eq.-5) then
if ((1.d0+Gamma).ge.0) then
G = sqrt(1.d0+Gamma)
dG = 1.d0/(2.d0*G)
else
G = -sqrt(-1.d0-Gamma)
dG = -1.d0/(2.d0*G)
endif
endif
return
end
cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
|
