box_parallelepiped.F90

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!! Copyright (C) 2002-2006 M. Marques, A. Castro, A. Rubio, G. Bertsch
!! Copyright (C) 2021 M. Oliveira, K. Lively, A. Obzhirov, I. Albar
!!
!! This program is free software; you can redistribute it and/or modify
!! it under the terms of the GNU General Public License as published by
!! the Free Software Foundation; either version 2, or (at your option)
!! any later version.
!!
!! This program is distributed in the hope that it will be useful,
!! but WITHOUT ANY WARRANTY; without even the implied warranty of
!! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
!! GNU General Public License for more details.
!!
!! You should have received a copy of the GNU General Public License
!! along with this program; if not, write to the Free Software
!! Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
!! 02110-1301, USA.
!!
 
#include "global.h"
 
module box_parallelepiped_oct_m
  use basis_vectors_oct_m
  use box_oct_m
  use box_shape_oct_m
  use debug_oct_m
  use global_oct_m
  use messages_oct_m
  use namespace_oct_m
  use profiling_oct_m
  use unit_oct_m
  use unit_system_oct_m
 
  implicit none
 
  private
  public :: box_parallelepiped_t
 
  type, extends(box_shape_t) :: box_parallelepiped_t
    private
    real(real64), allocatable, public :: half_length(:)
 
    integer, public :: n_periodic_boundaries = 0
  contains
    procedure :: shape_contains_points => box_parallelepiped_shape_contains_points
    procedure :: get_surface_points => box_parallelepiped_shape_get_surface_points
    procedure :: get_surface_point_info => box_parallelepiped_shape_get_surface_point_info
    procedure :: write_info => box_parallelepiped_write_info
    procedure :: short_info => box_parallelepiped_short_info
    procedure :: regenerate => box_parallelepiped_regenerate
    final     :: box_parallelepiped_finalize
  end type box_parallelepiped_t
 
  interface box_parallelepiped_t
    procedure box_parallelepiped_constructor
  end interface box_parallelepiped_t
 
contains
 
  !--------------------------------------------------------------
  function box_parallelepiped_constructor(dim, center, axes, length, namespace, n_periodic_boundaries) result(box)
    integer,            intent(in) :: dim
    real(real64),       intent(in) :: center(dim)
    real(real64),       intent(in) :: axes(dim, dim)
    real(real64),       intent(in) :: length(dim)
    type(namespace_t),  intent(in) :: namespace
    integer, optional,  intent(in) :: n_periodic_boundaries
    class(box_parallelepiped_t), pointer :: box
 
    push_sub(box_parallelepiped_constructor)
 
    ! Allocate memory
    safe_allocate(box)
 
    ! Initialize box
    safe_allocate(box%half_length(1:dim))
    box%half_length = m_half * length
 
    if (present(n_periodic_boundaries)) then
      box%n_periodic_boundaries = n_periodic_boundaries
    end if
    call box_shape_init(box, namespace, dim, center, bounding_box_min=-box%half_length, bounding_box_max=box%half_length, axes=axes)
 
    box%bounding_box_l = box%half_length + abs(center)
 
    pop_sub(box_parallelepiped_constructor)
  end function box_parallelepiped_constructor
 
  !--------------------------------------------------------------
  subroutine box_parallelepiped_regenerate(box, dim, axes, length, namespace)
    class(box_parallelepiped_t), intent(inout) :: box
    integer,                     intent(in) :: dim
    real(real64),                intent(in) :: axes(dim, dim)
    real(real64),                intent(in) :: length(dim)
    type(namespace_t),           intent(in) :: namespace
 
    real(real64) :: center(dim)
 
    push_sub(box_parallelepiped_regenerate)
 
    center = box%center
    safe_deallocate_a(box%center)
    safe_deallocate_a(box%bounding_box_l)
 
    ! Initialize box
    box%half_length = m_half * length
    call box_shape_init(box, namespace, dim, center, bounding_box_min=-box%half_length, bounding_box_max=box%half_length, axes=axes)
 
    box%bounding_box_l = box%half_length + abs(center)
 
    pop_sub(box_parallelepiped_regenerate)
  end subroutine box_parallelepiped_regenerate
 
 
  !--------------------------------------------------------------
  subroutine box_parallelepiped_finalize(this)
    type(box_parallelepiped_t), intent(inout) :: this
 
    push_sub(box_parallelepiped_finalize)
 
    call box_shape_end(this)
    safe_deallocate_a(this%half_length)
 
    pop_sub(box_parallelepiped_finalize)
  end subroutine box_parallelepiped_finalize
 
  !--------------------------------------------------------------
  function box_parallelepiped_shape_contains_points(this, nn, xx, tol) result(contained)
    class(box_parallelepiped_t), intent(in)  :: this
    integer,                     intent(in)  :: nn
    real(real64), contiguous,    intent(in)  :: xx(:,:)
    real(real64), optional,      intent(in)  :: tol
    logical :: contained(1:nn)
 
    integer :: ip, idir
    real(real64) :: ulimit(this%dim), llimit(this%dim), tol_
 
    tol_ = optional_default(tol, box_boundary_delta)
 
    llimit = this%center - this%half_length - tol_
    do idir = 1, this%dim
      if (idir <= this%n_periodic_boundaries) then
        ! When periodic, we exclude one of the faces from the box.
        ulimit(idir) = this%center(idir) + this%half_length(idir) - tol_
      else
        ulimit(idir) = this%center(idir) + this%half_length(idir) + tol_
      end if
    end do
 
    do ip = 1, nn
      contained(ip) = .true.
      do idir = 1, this%dim
        contained(ip) = contained(ip) .and. xx(ip, idir) >= llimit(idir) .and. xx(ip, idir) <= ulimit(idir)
        if (idir > this%n_periodic_boundaries) then
          ! We only consider the box to be inside out along the non-periodic directions.
          contained(ip) = contained(ip) .neqv. this%is_inside_out()
        end if
      end do
    end do
 
  end function box_parallelepiped_shape_contains_points
 
  !--------------------------------------------------------------
  function box_parallelepiped_shape_get_surface_points(this,namespace,mesh_spacing,nn,xx, number_of_layers) result(surface_points)
    class(box_parallelepiped_t), intent(in)  :: this
    type(namespace_t),  intent(in)  :: namespace
    real(real64),       intent(in)  :: mesh_spacing(:)
    integer,            intent(in)  :: nn
    real(real64),       intent(in)  :: xx(:,:)
    integer, optional,  intent(in)  :: number_of_layers
 
    logical :: surface_points(1:nn)
    integer :: idir, number_of_layers_
    real(real64)   :: shrink(this%dim), test_axis(this%dim)
    class(box_parallelepiped_t), pointer :: shrinked_box
 
    ! Check that each axis is along the Cartersian axis
    do idir = 1, this%dim
      test_axis = m_zero
      test_axis(idir) = m_one
      assert(all(abs(this%axes%vectors(:, idir) - test_axis(:)) < m_epsilon))
    end do
 
    number_of_layers_ = 1
    if (present(number_of_layers)) number_of_layers_ = number_of_layers
 
    ! Determine how much the shrink should be based on the spacing in each direction
    shrink(:) = 1 - number_of_layers_ * (1 - box_boundary_delta) * (mesh_spacing(:) / this%half_length(:))
 
    ! Then we create a shrunk parallelepiped box
    shrinked_box => box_parallelepiped_t(this%dim, this%center, this%axes%vectors, &
      m_two*this%half_length(:)*shrink(:), namespace)
 
    ! Then we look for points of the old box that are not containted in the smaller box
    ! box_parallelepiped_shape_contains_points will return the point contained in the shrinked box,
    ! but we are interested in the ones not contained, as they will the surface points of the original parallelepiped
    if (SIZE(xx, 1) == 3) then
      surface_points = .not. box_parallelepiped_shape_contains_points(shrinked_box, nn, transpose(xx))
    else
      surface_points = .not. box_parallelepiped_shape_contains_points(shrinked_box, nn, xx)
    end if
 
    safe_deallocate_p(shrinked_box)
  end function box_parallelepiped_shape_get_surface_points
 
  !--------------------------------------------------------------
  subroutine box_parallelepiped_shape_get_surface_point_info(this, point_coordinates,mesh_spacing, normal_vector, surface_element)
    class(box_parallelepiped_t), intent(in)  :: this
    real(real64),                intent(in)  :: point_coordinates(:)
    real(real64),                intent(in)  :: mesh_spacing(:)
    real(real64),                intent(out) :: normal_vector(:)
    real(real64),                intent(out) :: surface_element
 
    real(real64)   :: vector_norm
    integer :: idir, first_index, second_index, third_index, face_counter
 
    push_sub(box_parallelepiped_shape_get_surface_point_info)
 
    ! Compute the normal vector to the surface point
 
    ! For a parallelepiped, the normal vector to a point is simply a vector that has plus or minus one in the direction at
    ! which the face is pointing, and zero in the others. For instance, if the top face is facing the z direction, then
    ! the normal vector for all points in that face should be (0,0,1)
 
    ! So first of all we have to determine in which face we are. To do that let us divide the vector containing the coordinates
    ! of the point by the maximum length of the parallelepiped
    normal_vector(:) = (point_coordinates(:) - this%center(:)) / this%half_length(:)
    face_counter = m_zero
    surface_element = m_zero
 
    ! Loop over the three directions
    do idir = 1, this%dim
      ! Determine the indeces of the faces
      first_index = this%dim - mod(idir, this%dim)
      second_index = this%dim - mod(idir + 1, this%dim)
      third_index = this%dim - mod(idir + 2, this%dim)
      if (abs(normal_vector(first_index)) >= abs(normal_vector(second_index)) .and. &
        abs(normal_vector(first_index)) >= abs(normal_vector(third_index))) then
        ! Define the surface element for the first_index
        surface_element = mesh_spacing(second_index) * mesh_spacing(third_index)
        face_counter = face_counter + 1
        ! Now we check whether we are on the face or on a vertex or corner
        if (abs(normal_vector(second_index)) / abs(normal_vector(first_index)) < &
          m_one - m_half * mesh_spacing(second_index) / this%half_length(first_index)) then
          normal_vector(second_index) = m_zero
        end if
        if (abs(normal_vector(third_index)) / abs(normal_vector(first_index)) < &
          m_one - m_half * mesh_spacing(third_index) / this%half_length(first_index)) then
          normal_vector(third_index) = m_zero
        end if
      end if
    end do
 
    if (face_counter == 3) surface_element = surface_element * (m_three / m_four)
 
    ! Now if the point lies in a face, then the normalized_coordinates has one component which is one, and all the others are
    ! zero. If the point is on a vertex, more than one coordinate is non zero. the final step is to normalize the vector
    vector_norm = norm2(normal_vector(:))
    ! Normal vector should never be zero
    assert(vector_norm > m_epsilon)
    normal_vector(:) = normal_vector(:) / vector_norm
 
    pop_sub(box_parallelepiped_shape_get_surface_point_info)
  end subroutine box_parallelepiped_shape_get_surface_point_info
 
  !--------------------------------------------------------------
  subroutine box_parallelepiped_write_info(this, iunit, namespace)
    class(box_parallelepiped_t), intent(in) :: this
    integer,           optional, intent(in) :: iunit
    type(namespace_t), optional, intent(in) :: namespace
 
    integer :: idir
 
    push_sub(box_parallelepiped_write_info)
 
    write(message(1),'(2x,a)') 'Type = parallelepiped'
    write(message(2),'(2x,3a, 99(f8.3,a))') 'Lengths [', trim(units_abbrev(units_out%length)), '] = (', &
      (units_from_atomic(units_out%length, m_two*this%half_length(idir)), ',', idir = 1, this%dim - 1), &
      units_from_atomic(units_out%length, m_two*this%half_length(this%dim)), ')'
    call messages_info(2, iunit=iunit, namespace=namespace)
 
    pop_sub(box_parallelepiped_write_info)
  end subroutine box_parallelepiped_write_info
 
  !--------------------------------------------------------------
  character(len=BOX_INFO_LEN) function box_parallelepiped_short_info(this, unit_length) result(info)
    class(box_parallelepiped_t), intent(in) :: this
    type(unit_t),                intent(in) :: unit_length
 
    integer :: idir
 
    push_sub(box_parallelepiped_short_info)
 
    write(info, '(a,a,a,99(f11.6,a))') 'BoxShape = parallelepiped; Lengths [', trim(units_abbrev(unit_length)),'] = [', &
      (units_from_atomic(unit_length, m_two*this%half_length(idir)), ',', idir = 1, this%dim - 1), &
      units_from_atomic(unit_length, m_two*this%half_length(this%dim)), ']'
 
    pop_sub(box_parallelepiped_short_info)
  end function box_parallelepiped_short_info
 
end module box_parallelepiped_oct_m
 
!! Local Variables:
!! mode: f90
!! coding: utf-8
!! End: