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root/group/trunk/OOPSE/libmdtools/calc_charge_charge.F90
Revision: 1131
Committed: Thu Apr 22 21:33:55 2004 UTC (20 years, 4 months ago) by tim
File size: 5114 byte(s)
Log Message:
change the calculation of pressure tensor

File Contents

# Content
1 module charge_charge
2
3 use force_globals
4 use definitions
5 use atype_module
6 use vector_class
7 use simulation
8 use status
9 #ifdef IS_MPI
10 use mpiSimulation
11 #endif
12 implicit none
13
14 PRIVATE
15 real(kind=dp), save :: ecr = 0.0_DP
16 real(kind=dp), save :: rt = 0.0_DP
17 real(kind=dp), save :: pre = 0.0_DP
18 logical, save :: haveCutoffs = .false.
19 logical, save :: haveChargeMap = .false.
20
21 public::setCutoffsCharge
22 public::do_charge_pair
23
24 type :: ChargeList
25 real(kind=DP) :: charge = 0.0_DP
26 end type ChargeList
27
28 type(ChargeList), dimension(:), allocatable :: ChargeMap
29
30 contains
31
32 subroutine setCutoffsCharge(this_ecr, this_rt)
33 real(kind=dp), intent(in) :: this_ecr, this_rt
34 ecr = this_ecr
35 rt = this_rt
36
37 ! pre converts from fundamental charge to kcal/mol
38 pre = 332.06508_DP
39
40 haveCutoffs = .true.
41
42 return
43 end subroutine setCutoffsCharge
44
45 subroutine createChargeMap(status)
46 integer :: nAtypes
47 integer :: status
48 integer :: i
49 real (kind=DP) :: thisCharge
50 logical :: thisProperty
51
52 status = 0
53
54 nAtypes = getSize(atypes)
55
56 if (nAtypes == 0) then
57 status = -1
58 return
59 end if
60
61 if (.not. allocated(ChargeMap)) then
62 allocate(ChargeMap(nAtypes))
63 endif
64
65 do i = 1, nAtypes
66
67 call getElementProperty(atypes, i, "is_Charge", thisProperty)
68
69 if (thisProperty) then
70 call getElementProperty(atypes, i, "charge", thisCharge)
71 ChargeMap(i)%charge = thisCharge
72 endif
73
74 end do
75
76 haveChargeMap = .true.
77
78 end subroutine createChargeMap
79
80
81 subroutine do_charge_pair(atom1, atom2, d, rij, r2, pot, f, &
82 do_pot, do_stress)
83
84 logical :: do_pot, do_stress
85
86 integer atom1, atom2, me1, me2, id1, id2
87 integer :: localError
88 real(kind=dp) :: rij, r2, q1, q2
89 real(kind=dp) :: drdx, drdy, drdz, dudr, fx, fy, fz
90 real(kind=dp) :: taper, dtdr, vterm
91
92 real( kind = dp ) :: pot
93 real( kind = dp ), dimension(3) :: d
94 real( kind = dp ), dimension(3,nLocal) :: f
95
96 if (.not. haveCutoffs) then
97 write(default_error,*) 'charge-charge does not have cutoffs set!'
98 return
99 endif
100
101 if (.not.haveChargeMap) then
102 localError = 0
103 call createChargeMap(localError)
104 if ( localError .ne. 0 ) then
105 call handleError("charge-charge", "ChargeMap creation failed!")
106 return
107 end if
108 endif
109
110 #ifdef IS_MPI
111 me1 = atid_Row(atom1)
112 me2 = atid_Col(atom2)
113 #else
114 me1 = atid(atom1)
115 me2 = atid(atom2)
116 #endif
117
118
119 q1 = ChargeMap(me1)%charge
120 q2 = ChargeMap(me2)%charge
121
122 if (rij.le.ecr) then
123
124 if (rij.lt.rt) then
125 taper = 1.0d0
126 dtdr = 0.0d0
127 else
128 taper = (ecr + 2.0d0*rij - 3.0d0*rt)*(ecr-rij)**2/ ((ecr-rt)**3)
129 dtdr = 6.0d0*(rij*rij - rij*rt - rij*ecr +ecr*rt)/((ecr-rt)**3)
130 endif
131
132 vterm = pre * q1 * q2 / rij
133
134 !!if(rij .le. 1.5) then
135 !! write(*,*) atom1, atom2, q1, q2, rij, vterm
136 !!endif
137
138 dudr = vterm * ( dtdr - taper / rij )
139
140 drdx = d(1) / rij
141 drdy = d(2) / rij
142 drdz = d(3) / rij
143
144 fx = dudr * drdx
145 fy = dudr * drdy
146 fz = dudr * drdz
147
148
149 #ifdef IS_MPI
150 if (do_pot) then
151 pot_Row(atom1) = pot_Row(atom1) + vterm*taper*0.5
152 pot_Col(atom2) = pot_Col(atom2) + vterm*taper*0.5
153 endif
154
155 f_Row(1,atom1) = f_Row(1,atom1) + fx
156 f_Row(2,atom1) = f_Row(2,atom1) + fy
157 f_Row(3,atom1) = f_Row(3,atom1) + fz
158
159 f_Col(1,atom2) = f_Col(1,atom2) - fx
160 f_Col(2,atom2) = f_Col(2,atom2) - fy
161 f_Col(3,atom2) = f_Col(3,atom2) - fz
162
163 #else
164
165 if (do_pot) pot = pot + vterm*taper
166
167 f(1,atom1) = f(1,atom1) + fx
168 f(2,atom1) = f(2,atom1) + fy
169 f(3,atom1) = f(3,atom1) + fz
170
171 f(1,atom2) = f(1,atom2) - fx
172 f(2,atom2) = f(2,atom2) - fy
173 f(3,atom2) = f(3,atom2) - fz
174
175 #endif
176
177 if (do_stress) then
178
179 #ifdef IS_MPI
180 id1 = tagRow(atom1)
181 id2 = tagColumn(atom2)
182 #else
183 id1 = atom1
184 id2 = atom2
185 #endif
186
187
188 if (molMembershipList(id1) .ne. molMembershipList(id2)) then
189
190 ! because the d vector is the rj - ri vector, and
191 ! because fx, fy, fz are the force on atom i, we need a
192 ! negative sign here:
193
194 tau_Temp(1) = tau_Temp(1) - d(1) * fx
195 tau_Temp(2) = tau_Temp(2) - d(1) * fy
196 tau_Temp(3) = tau_Temp(3) - d(1) * fz
197 tau_Temp(4) = tau_Temp(4) - d(2) * fx
198 tau_Temp(5) = tau_Temp(5) - d(2) * fy
199 tau_Temp(6) = tau_Temp(6) - d(2) * fz
200 tau_Temp(7) = tau_Temp(7) - d(3) * fx
201 tau_Temp(8) = tau_Temp(8) - d(3) * fy
202 tau_Temp(9) = tau_Temp(9) - d(3) * fz
203
204 virial_Temp = virial_Temp + &
205 (tau_Temp(1) + tau_Temp(5) + tau_Temp(9))
206
207 endif
208 endif
209
210 endif
211 return
212 end subroutine do_charge_pair
213
214 end module charge_charge