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 Some auxiliary functions and subroutines needed for HFX calculations
      10              : !> \par History
      11              : !>      04.2008 created [Manuel Guidon]
      12              : !> \author Manuel Guidon
      13              : ! **************************************************************************************************
      14              : MODULE hfx_helpers
      15              : #include "./base/base_uses.f90"
      16              :    IMPLICIT NONE
      17              :    PRIVATE
      18              : 
      19              :    PUBLIC :: count_cells_perd, &
      20              :              next_image_cell_perd
      21              : 
      22              :    CHARACTER(len=*), PARAMETER, PRIVATE :: moduleN = 'hfx_helpers'
      23              : 
      24              : !***
      25              : 
      26              : CONTAINS
      27              : 
      28              : ! **************************************************************************************************
      29              : !> \brief - Auxiliary function for creating periodic neighbor cells
      30              : !> \param shell number of shells in each coordinate direction
      31              : !> \param perd ...
      32              : !> \return ...
      33              : !> \par History
      34              : !>      09.2007 created [Manuel Guidon]
      35              : !> \author Manuel Guidon
      36              : ! **************************************************************************************************
      37         2817 :    FUNCTION count_cells_perd(shell, perd)
      38              :       INTEGER, INTENT(IN)                                :: shell, perd(3)
      39              :       INTEGER                                            :: count_cells_perd
      40              : 
      41              :       INTEGER                                            :: i, j, k
      42              : 
      43         2817 :       count_cells_perd = 0
      44         6082 :       DO i = -shell*perd(1), shell*perd(1)
      45        11107 :          DO j = -shell*perd(2), shell*perd(2)
      46        20675 :             DO k = -shell*perd(3), shell*perd(3)
      47        17410 :                IF ((i**2 + j**2 + k**2 == shell)) count_cells_perd = count_cells_perd + 1
      48              :             END DO
      49              :          END DO
      50              :       END DO
      51         2817 :    END FUNCTION count_cells_perd
      52              : 
      53              : ! **************************************************************************************************
      54              : !> \brief - Auxiliary function for creating periodic neighbor cells
      55              : !> \param m ...
      56              : !> \param perd ...
      57              : !> \par History
      58              : !>      09.2007 created [Manuel Guidon]
      59              : !> \author Manuel Guidon
      60              : ! **************************************************************************************************
      61         3257 :    SUBROUTINE next_image_cell_perd(m, perd)
      62              :       INTEGER                                            :: m(3)
      63              :       INTEGER, INTENT(IN)                                :: perd(3)
      64              : 
      65              :       INTEGER                                            :: i, j, k, shell
      66              :       LOGICAL                                            :: found
      67              : 
      68         3257 :       found = .FALSE.
      69        13028 :       shell = SUM(m**2)
      70         2671 :       outer: DO
      71         9893 :          DO i = -shell*perd(1), shell*perd(1)
      72        21997 :          DO j = -shell*perd(2), shell*perd(2)
      73        64957 :             inner: DO k = -shell*perd(3), shell*perd(3)
      74        48888 :                IF (.NOT. (i**2 + j**2 + k**2 == shell)) CYCLE inner
      75         9130 :                IF (found) THEN
      76        13028 :                   m = [i, j, k]
      77              :                   EXIT outer
      78              :                END IF
      79        68498 :                IF (ALL(M == [i, j, k])) found = .TRUE.
      80              :             END DO inner
      81              :          END DO
      82              :          END DO
      83         2671 :          shell = shell + 1
      84              :       END DO outer
      85         3257 :    END SUBROUTINE next_image_cell_perd
      86              : 
      87              : ! **************************************************************************************************
      88              : 
      89              : END MODULE hfx_helpers