Line data Source code
1 : !--------------------------------------------------------------------------------------------------!
2 : ! CP2K: A general program to perform molecular dynamics simulations !
3 : ! Copyright 2000-2025 CP2K developers group <https://cp2k.org> !
4 : ! !
5 : ! SPDX-License-Identifier: GPL-2.0-or-later !
6 : !--------------------------------------------------------------------------------------------------!
7 :
8 : ! **************************************************************************************************
9 : !> \brief Interface to Maxwell equation solver
10 : !> \par History
11 : !> 11/2020 created [mbrehm]
12 : !> \author Martin Brehm
13 : ! **************************************************************************************************
14 : MODULE maxwell_solver_interface
15 : USE cp_control_types, ONLY: maxwell_control_type
16 : USE cp_log_handling, ONLY: cp_get_default_logger, &
17 : cp_logger_get_default_io_unit, &
18 : cp_logger_type
19 : USE kinds, ONLY: dp
20 : USE pw_types, ONLY: pw_r3d_rs_type
21 : USE ISO_C_BINDING, ONLY: C_INT, C_DOUBLE
22 :
23 : #include "./base/base_uses.f90"
24 :
25 : IMPLICIT NONE
26 :
27 : PRIVATE
28 :
29 : CHARACTER(len=*), PARAMETER, PRIVATE :: moduleN = 'maxwell_solver_interface'
30 :
31 : ! *** Public subroutines ***
32 : PUBLIC :: maxwell_solver
33 :
34 : #if defined(__LIBMAXWELL)
35 :
36 : INTERFACE
37 :
38 : INTEGER(C_INT) FUNCTION libcp2kmw_setgrid(rx, ry, rz, ax, ay, az, bx, by, bz, cx, cy, cz) BIND(C, NAME='libcp2kmw_setgrid')
39 : USE ISO_C_BINDING, ONLY: C_INT, C_DOUBLE
40 : IMPLICIT NONE
41 : INTEGER(C_INT) :: rx, ry, rz
42 : REAL(C_DOUBLE) :: ax, ay, az, bx, by, bz, cx, cy, cz
43 : END FUNCTION libcp2kmw_setgrid
44 :
45 : INTEGER(C_INT) FUNCTION libcp2kmw_step(step, t) BIND(C, NAME='libcp2kmw_step')
46 : USE ISO_C_BINDING, ONLY: C_INT, C_DOUBLE
47 : IMPLICIT NONE
48 : INTEGER(C_INT) :: step
49 : REAL(C_DOUBLE) :: t
50 : END FUNCTION libcp2kmw_step
51 :
52 : INTEGER(C_INT) FUNCTION libcp2kmw_getzrow(buf, px, py, zmin, zmax) BIND(C, NAME='libcp2kmw_getzrow')
53 : USE ISO_C_BINDING, ONLY: C_INT, C_DOUBLE
54 : IMPLICIT NONE
55 : REAL(C_DOUBLE) :: buf(*)
56 : INTEGER(C_INT) :: px, py, zmin, zmax
57 : END FUNCTION libcp2kmw_getzrow
58 :
59 : END INTERFACE
60 :
61 : #endif
62 :
63 : CONTAINS
64 :
65 : ! **************************************************************************************************
66 : !> \brief Computes the external potential on the grid
67 : !> \param maxwell_control the Maxwell control section
68 : !> \param v_ee the realspace grid with the potential
69 : !> \param sim_step current simulation step
70 : !> \param sim_time current physical simulation time
71 : !> \param scaling_factor a factor to scale the potential with
72 : !> \date 12/2020
73 : !> \author Martin Brehm
74 : ! **************************************************************************************************
75 0 : SUBROUTINE maxwell_solver(maxwell_control, v_ee, sim_step, sim_time, scaling_factor)
76 : TYPE(maxwell_control_type), INTENT(IN) :: maxwell_control
77 : TYPE(pw_r3d_rs_type), POINTER :: v_ee
78 : INTEGER, INTENT(IN) :: sim_step
79 : REAL(KIND=dp), INTENT(IN) :: sim_time
80 : REAL(KIND=dp), INTENT(IN) :: scaling_factor
81 :
82 : #if defined(__LIBMAXWELL)
83 :
84 : CHARACTER(len=*), PARAMETER :: routineN = 'maxwell_solver'
85 :
86 : INTEGER :: handle, iounit, res, my_rank, num_pe, &
87 : gid, master, tag, i, j, ip
88 : TYPE(cp_logger_type), POINTER :: logger
89 :
90 : INTEGER, DIMENSION(3) :: lbounds, lbounds_local, npoints, &
91 : npoints_local, ubounds, ubounds_local
92 : REAL(C_DOUBLE), ALLOCATABLE, DIMENSION(:) :: buffer
93 :
94 : MARK_USED(maxwell_control)
95 : MARK_USED(v_ee)
96 : MARK_USED(sim_step)
97 : MARK_USED(sim_time)
98 :
99 : CALL timeset(routineN, handle)
100 : NULLIFY (logger)
101 : logger => cp_get_default_logger()
102 : iounit = cp_logger_get_default_io_unit(logger)
103 :
104 : my_rank = v_ee%pw_grid%para%group%mepos
105 : num_pe = v_ee%pw_grid%para%group%num_pe
106 : gid = v_ee%pw_grid%para%group
107 : tag = 1
108 :
109 : lbounds = v_ee%pw_grid%bounds(1, :)
110 : ubounds = v_ee%pw_grid%bounds(2, :)
111 : npoints = v_ee%pw_grid%npts
112 :
113 : lbounds_local = v_ee%pw_grid%bounds_local(1, :)
114 : ubounds_local = v_ee%pw_grid%bounds_local(2, :)
115 : npoints_local = v_ee%pw_grid%npts_local
116 :
117 : ALLOCATE (buffer(lbounds(3):ubounds(3)))
118 :
119 : IF (my_rank == 0) THEN
120 :
121 : IF (iounit > 0) THEN
122 : WRITE (iounit, *) ""
123 : WRITE (iounit, *) "MAXWELL| Called, step = ", sim_step, " time = ", sim_time
124 : END IF
125 :
126 : res = libcp2kmw_setgrid( &
127 : ubounds(1) - lbounds(1) + 1, &
128 : ubounds(2) - lbounds(2) + 1, &
129 : ubounds(3) - lbounds(3) + 1, &
130 : v_ee%pw_grid%dh(1, 1)*(ubounds(1) - lbounds(1) + 1), &
131 : v_ee%pw_grid%dh(2, 1)*(ubounds(1) - lbounds(1) + 1), &
132 : v_ee%pw_grid%dh(3, 1)*(ubounds(1) - lbounds(1) + 1), &
133 : v_ee%pw_grid%dh(1, 2)*(ubounds(2) - lbounds(2) + 1), &
134 : v_ee%pw_grid%dh(2, 2)*(ubounds(2) - lbounds(2) + 1), &
135 : v_ee%pw_grid%dh(3, 2)*(ubounds(2) - lbounds(2) + 1), &
136 : v_ee%pw_grid%dh(1, 3)*(ubounds(3) - lbounds(3) + 1), &
137 : v_ee%pw_grid%dh(2, 3)*(ubounds(3) - lbounds(3) + 1), &
138 : v_ee%pw_grid%dh(3, 3)*(ubounds(3) - lbounds(3) + 1) &
139 : )
140 :
141 : res = libcp2kmw_step(sim_step, sim_time)
142 :
143 : IF (iounit > 0) THEN
144 : WRITE (iounit, *) "MAXWELL| Returned with value ", res
145 : WRITE (iounit, *) "MAXWELL| Distributing potential to MPI processes..."
146 : END IF
147 :
148 : END IF
149 :
150 : ! The following code block is copied from src/pw/realspace_grid_cube.F
151 : CALL gid%bcast(buffer(lbounds(3):ubounds(3)), 0)
152 :
153 : !master sends all data to everyone
154 : DO i = lbounds(1), ubounds(1)
155 : DO j = lbounds(2), ubounds(2)
156 :
157 : !only use data that is local to me - i.e. in slice of pencil I own
158 : IF ((lbounds_local(1) <= i) .AND. (i <= ubounds_local(1)) .AND. &
159 : (lbounds_local(2) <= j) .AND. (j <= ubounds_local(2))) THEN
160 : !allow scaling of external potential values by factor 'scaling' (SCALING_FACTOR in input file)
161 : v_ee%array(i, j, lbounds(3):ubounds(3)) = buffer(lbounds(3):ubounds(3))*scaling_factor
162 : END IF
163 :
164 : END DO
165 : END DO
166 :
167 : IF (iounit > 0) THEN
168 : WRITE (iounit, *) "MAXWELL| All done."
169 : END IF
170 :
171 : CALL timestop(handle)
172 :
173 : #else
174 :
175 : MARK_USED(maxwell_control)
176 : MARK_USED(v_ee)
177 : MARK_USED(sim_step)
178 : MARK_USED(sim_time)
179 : MARK_USED(scaling_factor)
180 :
181 : CALL cp_abort(__LOCATION__, &
182 : "The Maxwell solver interface requires CP2k to be compiled &
183 0 : &with the -D__LIBMAXWELL preprocessor option.")
184 :
185 : #endif
186 :
187 0 : END SUBROUTINE maxwell_solver
188 :
189 : END MODULE maxwell_solver_interface
190 :
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