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root/group/trunk/OOPSE/libmdtools/calc_dipole_dipole.F90
Revision: 394
Committed: Mon Mar 24 21:55:34 2003 UTC (21 years, 3 months ago) by gezelter
File size: 6217 byte(s)
Log Message:
electrostatic changes for dipole / RF separation

File Contents

# User Rev Content
1 mmeineke 377 module dipole_dipole
2    
3     use force_globals
4     use definitions
5     use atype_module
6     use vector_class
7     #ifdef IS_MPI
8     use mpiSimulation
9     #endif
10     implicit none
11    
12     real(kind=dp), save :: rrf
13     real(kind=dp), save :: rt
14     real(kind=dp), save :: rrfsq
15     real(kind=dp), save :: pre
16     logical, save :: dipole_initialized = .false.
17    
18     contains
19    
20     subroutine initialize_dipole(this_rrf, this_rt)
21     real(kind=dp), intent(in) :: this_rrf, this_rt
22     rrf = this_rrf
23     rt = this_rt
24     rrfsq = rrf * rrf
25     ! pre converts from mu in units of debye to kcal/mol
26 chuckv 388 pre = 14.38362_dp
27 gezelter 394
28    
29     write(*,*) 'rrf = ', rrf
30     write(*,*) 'rt = ', rt
31     write(*,*) 'pre = ', pre
32 mmeineke 377
33     dipole_initialized = .true.
34    
35     return
36     end subroutine initialize_dipole
37    
38    
39     subroutine do_dipole_pair(atom1, atom2, d, rij, r2, pot, u_l, f, t, &
40     do_pot, do_stress)
41    
42     logical :: do_pot, do_stress
43    
44     integer atom1, atom2, me1, me2
45     real(kind=dp) :: rij, mu1, mu2
46     real(kind=dp) :: dfact1, dfact2, dip2, r2, r3, r5, pre
47     real(kind=dp) :: dudx, dudy, dudz, dudu1x, dudu1y, dudu1z
48     real(kind=dp) :: dudu2x, dudu2y, dudu2z, rdotu1, rdotu2, u1dotu2
49     real(kind=dp) :: taper, dtdr, vterm
50    
51     real( kind = dp ) :: pot
52     real( kind = dp ), dimension(3) :: d
53     real( kind = dp ), dimension(:,:) :: u_l
54     real( kind = dp ), dimension(:,:) :: f
55     real( kind = dp ), dimension(:,:) :: t
56    
57     real (kind = dp), dimension(3) :: ul1
58     real (kind = dp), dimension(3) :: ul2
59    
60     if (.not.dipole_initialized) then
61     write(default_error,*) 'Dipole-dipole not initialized!'
62     return
63     endif
64    
65     #ifdef IS_MPI
66     me1 = atid_Row(atom1)
67     ul1(1) = u_l_Row(1,atom1)
68     ul1(2) = u_l_Row(2,atom1)
69     ul1(3) = u_l_Row(3,atom1)
70    
71     me2 = atid_Col(atom2)
72     ul2(1) = u_l_Col(1,atom2)
73     ul2(2) = u_l_Col(2,atom2)
74     ul2(3) = u_l_Col(3,atom2)
75     #else
76     me1 = atid(atom1)
77     ul1(1) = u_l(1,atom1)
78     ul1(2) = u_l(2,atom1)
79     ul1(3) = u_l(3,atom1)
80    
81     me2 = atid(atom2)
82     ul2(1) = u_l(1,atom2)
83     ul2(2) = u_l(2,atom2)
84     ul2(3) = u_l(3,atom2)
85     #endif
86    
87     call getElementProperty(atypes, me1, "dipole_moment", mu1)
88     call getElementProperty(atypes, me2, "dipole_moment", mu2)
89 chuckv 388
90 mmeineke 377 if (rij.le.rrf) then
91    
92     if (rij.lt.rt) then
93     taper = 1.0d0
94     dtdr = 0.0d0
95     else
96     taper = (rrf + 2.0d0*rij - 3.0d0*rt)*(rrf-rij)**2/ ((rrf-rt)**3)
97     dtdr = 6.0d0*(rij*rij - rij*rt - rij*rrf +rrf*rt)/((rrf-rt)**3)
98     endif
99    
100     r3 = r2*rij
101     r5 = r3*r2
102    
103     rdotu1 = d(1)*ul1(1) + d(2)*ul1(2) + d(3)*ul1(3)
104     rdotu2 = d(1)*ul2(1) + d(2)*ul2(2) + d(3)*ul2(3)
105     u1dotu2 = ul1(1)*ul2(1) + ul1(2)*ul2(2) + ul1(3)*ul2(3)
106    
107     dip2 = pre * mu1 * mu2
108    
109     dfact1 = 3.0d0*dip2 / r2
110     dfact2 = 3.0d0*dip2 / r5
111    
112     vterm = dip2*((u1dotu2/r3) - 3.0d0*(rdotu1*rdotu2/r5))
113    
114     if (do_pot) then
115     #ifdef IS_MPI
116     pot_row(atom1) = pot_row(atom1) + 0.5d0*vterm*taper
117     pot_col(atom2) = pot_col(atom2) + 0.5d0*vterm*taper
118     #else
119     pot = pot + vterm*taper
120     #endif
121     endif
122    
123     dudx = (-dfact1 * d(1) * ((u1dotu2/r3) - &
124     (5.0d0*(rdotu1*rdotu2)/r5)) - &
125     dfact2*(ul1(1)*rdotu2 + ul2(1)*rdotu1))*taper + &
126     vterm*dtdr*d(1)/rij
127    
128     dudy = (-dfact1 * d(2) * ((u1dotu2/r3) - &
129     (5.0d0*(rdotu1*rdotu2)/r5)) - &
130     dfact2*(ul1(2)*rdotu2 + ul2(2)*rdotu1))*taper + &
131     vterm*dtdr*d(2)/rij
132    
133     dudz = (-dfact1 * d(3) * ((u1dotu2/r3) - &
134     (5.0d0*(rdotu1*rdotu2)/r5)) - &
135     dfact2*(ul1(3)*rdotu2 + ul2(3)*rdotu1))*taper + &
136     vterm*dtdr*d(3)/rij
137    
138     dudu1x = (dip2*((ul2(1)/r3) - (3.0d0*d(1)*rdotu2/r5)))*taper
139     dudu1y = (dip2*((ul2(2)/r3) - (3.0d0*d(2)*rdotu2/r5)))*taper
140     dudu1z = (dip2*((ul2(3)/r3) - (3.0d0*d(3)*rdotu2/r5)))*taper
141    
142     dudu2x = (dip2*((ul1(1)/r3) - (3.0d0*d(1)*rdotu1/r5)))*taper
143     dudu2y = (dip2*((ul1(2)/r3) - (3.0d0*d(2)*rdotu1/r5)))*taper
144     dudu2z = (dip2*((ul1(3)/r3) - (3.0d0*d(3)*rdotu1/r5)))*taper
145    
146    
147     #ifdef IS_MPI
148 gezelter 394 f_Row(1,atom1) = f_Row(1,atom1) - dudx
149     f_Row(2,atom1) = f_Row(2,atom1) - dudy
150     f_Row(3,atom1) = f_Row(3,atom1) - dudz
151 mmeineke 377
152 gezelter 394 f_Col(1,atom2) = f_Col(1,atom2) + dudx
153     f_Col(2,atom2) = f_Col(2,atom2) + dudy
154     f_Col(3,atom2) = f_Col(3,atom2) + dudz
155 mmeineke 377
156     t_Row(1,atom1) = t_Row(1,atom1) - ul1(2)*dudu1z + ul1(3)*dudu1y
157     t_Row(2,atom1) = t_Row(2,atom1) - ul1(3)*dudu1x + ul1(1)*dudu1z
158     t_Row(3,atom1) = t_Row(3,atom1) - ul1(1)*dudu1y + ul1(2)*dudu1x
159    
160     t_Col(1,atom2) = t_Col(1,atom2) - ul2(2)*dudu2z + ul2(3)*dudu2y
161     t_Col(2,atom2) = t_Col(2,atom2) - ul2(3)*dudu2x + ul2(1)*dudu2z
162     t_Col(3,atom2) = t_Col(3,atom2) - ul2(1)*dudu2y + ul2(2)*dudu2x
163     #else
164 gezelter 394 f(1,atom1) = f(1,atom1) - dudx
165     f(2,atom1) = f(2,atom1) - dudy
166     f(3,atom1) = f(3,atom1) - dudz
167 mmeineke 377
168 gezelter 394 f(1,atom2) = f(1,atom2) + dudx
169     f(2,atom2) = f(2,atom2) + dudy
170     f(3,atom2) = f(3,atom2) + dudz
171 mmeineke 377
172     t(1,atom1) = t(1,atom1) - ul1(2)*dudu1z + ul1(3)*dudu1y
173     t(2,atom1) = t(2,atom1) - ul1(3)*dudu1x + ul1(1)*dudu1z
174     t(3,atom1) = t(3,atom1) - ul1(1)*dudu1y + ul1(2)*dudu1x
175    
176     t(1,atom2) = t(1,atom2) - ul2(2)*dudu2z + ul2(3)*dudu2y
177     t(2,atom2) = t(2,atom2) - ul2(3)*dudu2x + ul2(1)*dudu2z
178     t(3,atom2) = t(3,atom2) - ul2(1)*dudu2y + ul2(2)*dudu2x
179     #endif
180    
181     if (do_stress) then
182     tau_Temp(1) = tau_Temp(1) + dudx * d(1)
183     tau_Temp(2) = tau_Temp(2) + dudx * d(2)
184     tau_Temp(3) = tau_Temp(3) + dudx * d(3)
185     tau_Temp(4) = tau_Temp(4) + dudy * d(1)
186     tau_Temp(5) = tau_Temp(5) + dudy * d(2)
187     tau_Temp(6) = tau_Temp(6) + dudy * d(3)
188     tau_Temp(7) = tau_Temp(7) + dudz * d(1)
189     tau_Temp(8) = tau_Temp(8) + dudz * d(2)
190     tau_Temp(9) = tau_Temp(9) + dudz * d(3)
191     virial_Temp = virial_Temp + (tau_Temp(1) + tau_Temp(5) + tau_Temp(9))
192     endif
193    
194     endif
195    
196     return
197     end subroutine do_dipole_pair
198    
199     end module dipole_dipole