add_coordination_number_hessian Subroutine

public subroutine add_coordination_number_hessian(mol, trans, cutoff, rcov, en, dEdcn, hessian, error)

Add the second derivative of the D4 coordination number contracted with the derivative of the energy w.r.t. the coordination number.

Arguments

Type IntentOptional Attributes Name
type(structure_type), intent(in) :: mol

Molecular structure data
real(kind=wp), intent(in) :: trans(:,:)

Lattice points
real(kind=wp), intent(in) :: cutoff

Real space cutoff
real(kind=wp), intent(in) :: rcov(:)

Covalent radius
real(kind=wp), intent(in) :: en(:)

Electronegativity
real(kind=wp), intent(in) :: dEdcn(:)

Derivative of expression with respect to the coordination number
real(kind=wp), intent(inout) :: hessian(:,:)

Second derivative of the energy w.r.t. the Cartesian coordinates
type(error_type), intent(out), optional, allocatable :: error

Error on failure; results are NaN if initialization fails.

Source Code

subroutine add_coordination_number_hessian(mol, trans, cutoff, rcov, en, dEdcn, hessian, error)

   !> Molecular structure data
   type(structure_type), intent(in) :: mol

   !> Lattice points
   real(wp), intent(in) :: trans(:, :)

   !> Real space cutoff
   real(wp), intent(in) :: cutoff

   !> Covalent radius
   real(wp), intent(in) :: rcov(:)

   !> Electronegativity
   real(wp), intent(in) :: en(:)

   !> Derivative of expression with respect to the coordination number
   real(wp), intent(in) :: dEdcn(:)

   !> Second derivative of the energy w.r.t. the Cartesian coordinates
   real(wp), intent(inout) :: hessian(:, :)

   !> Error on failure; results are NaN if initialization fails.
   type(error_type), allocatable, intent(out), optional :: error

   class(ncoord_type), allocatable :: ncoord
   type(error_type), allocatable :: local_error

   call new_ncoord(ncoord, mol, cn_count%dftd4, &
      & kcn=default_kcn, cutoff=cutoff, rcov=rcov, en=en, error=local_error)
   if (allocated(local_error)) then
      hessian = ieee_value(0.0_wp, ieee_quiet_nan)
      if (present(error)) call move_alloc(local_error, error)
      return
   end if

   call ncoord%add_coordination_number_hessian(mol, trans, dEdcn, hessian)

end subroutine add_coordination_number_hessian