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root/group/trunk/OOPSE/libmdtools/calc_charge_charge.F90
Revision: 1160
Committed: Tue May 11 21:31:15 2004 UTC (20 years, 2 months ago) by gezelter
File size: 4068 byte(s)
Log Message:
Fortran-side changes for group-based cutoffs

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
16 real(kind=dp), parameter :: pre = 332.06508_DP
17 logical, save :: haveChargeMap = .false.
18
19 public::do_charge_pair
20
21 type :: ChargeList
22 real(kind=DP) :: charge = 0.0_DP
23 end type ChargeList
24
25 type(ChargeList), dimension(:), allocatable :: ChargeMap
26
27 contains
28
29 subroutine createChargeMap(status)
30 integer :: nAtypes
31 integer :: status
32 integer :: i
33 real (kind=DP) :: thisCharge
34 logical :: thisProperty
35
36 status = 0
37
38 nAtypes = getSize(atypes)
39
40 if (nAtypes == 0) then
41 status = -1
42 return
43 end if
44
45 if (.not. allocated(ChargeMap)) then
46 allocate(ChargeMap(nAtypes))
47 endif
48
49 do i = 1, nAtypes
50
51 call getElementProperty(atypes, i, "is_Charge", thisProperty)
52
53 if (thisProperty) then
54 call getElementProperty(atypes, i, "charge", thisCharge)
55 ChargeMap(i)%charge = thisCharge
56 endif
57
58 end do
59
60 haveChargeMap = .true.
61
62 end subroutine createChargeMap
63
64 subroutine do_charge_pair(atom1, atom2, d, rij, r2, sw, vpair, &
65 pot, f, do_pot, do_stress)
66
67 logical :: do_pot, do_stress
68
69 integer atom1, atom2, me1, me2, id1, id2
70 integer :: localError
71 real(kind=dp) :: rij, r2, q1, q2, sw, vpair
72 real(kind=dp) :: drdx, drdy, drdz, dudr, fx, fy, fz
73 real(kind=dp) :: vterm
74
75 real( kind = dp ) :: pot
76 real( kind = dp ), dimension(3) :: d
77 real( kind = dp ), dimension(3,nLocal) :: f
78
79 if (.not.haveChargeMap) then
80 localError = 0
81 call createChargeMap(localError)
82 if ( localError .ne. 0 ) then
83 call handleError("charge-charge", "ChargeMap creation failed!")
84 return
85 end if
86 endif
87
88 #ifdef IS_MPI
89 me1 = atid_Row(atom1)
90 me2 = atid_Col(atom2)
91 #else
92 me1 = atid(atom1)
93 me2 = atid(atom2)
94 #endif
95
96 q1 = ChargeMap(me1)%charge
97 q2 = ChargeMap(me2)%charge
98
99 vterm = pre * q1 * q2 / rij
100
101 dudr = -sw * vterm / rij
102
103 drdx = d(1) / rij
104 drdy = d(2) / rij
105 drdz = d(3) / rij
106
107 fx = dudr * drdx
108 fy = dudr * drdy
109 fz = dudr * drdz
110
111 vpair = vpair + vterm
112
113 #ifdef IS_MPI
114 if (do_pot) then
115 pot_Row(atom1) = pot_Row(atom1) + sw*vterm*0.5
116 pot_Col(atom2) = pot_Col(atom2) + sw*vterm*0.5
117 endif
118
119 f_Row(1,atom1) = f_Row(1,atom1) + fx
120 f_Row(2,atom1) = f_Row(2,atom1) + fy
121 f_Row(3,atom1) = f_Row(3,atom1) + fz
122
123 f_Col(1,atom2) = f_Col(1,atom2) - fx
124 f_Col(2,atom2) = f_Col(2,atom2) - fy
125 f_Col(3,atom2) = f_Col(3,atom2) - fz
126
127 #else
128
129 if (do_pot) pot = pot + sw*vterm
130
131 f(1,atom1) = f(1,atom1) + fx
132 f(2,atom1) = f(2,atom1) + fy
133 f(3,atom1) = f(3,atom1) + fz
134
135 f(1,atom2) = f(1,atom2) - fx
136 f(2,atom2) = f(2,atom2) - fy
137 f(3,atom2) = f(3,atom2) - fz
138
139 #endif
140
141 if (do_stress) then
142
143 #ifdef IS_MPI
144 id1 = tagRow(atom1)
145 id2 = tagColumn(atom2)
146 #else
147 id1 = atom1
148 id2 = atom2
149 #endif
150
151
152 if (molMembershipList(id1) .ne. molMembershipList(id2)) then
153
154 ! because the d vector is the rj - ri vector, and
155 ! because fx, fy, fz are the force on atom i, we need a
156 ! negative sign here:
157
158 tau_Temp(1) = tau_Temp(1) - d(1) * fx
159 tau_Temp(2) = tau_Temp(2) - d(1) * fy
160 tau_Temp(3) = tau_Temp(3) - d(1) * fz
161 tau_Temp(4) = tau_Temp(4) - d(2) * fx
162 tau_Temp(5) = tau_Temp(5) - d(2) * fy
163 tau_Temp(6) = tau_Temp(6) - d(2) * fz
164 tau_Temp(8) = tau_Temp(8) - d(3) * fy
165 tau_Temp(9) = tau_Temp(9) - d(3) * fz
166
167
168 virial_Temp = virial_Temp + &
169 (tau_Temp(1) + tau_Temp(5) + tau_Temp(9))
170
171 endif
172 endif
173
174
175 return
176 end subroutine do_charge_pair
177
178 end module charge_charge