ncoord_type Derived Type

type, public, abstract :: ncoord_type

Abstract base class for coordination number evaluator


Components

Type Visibility Attributes Name Initial
real(kind=wp), public :: cut = -1.0_wp

Cutoff for the maximum coordination number (negative value, no cutoff)
real(kind=wp), public :: cutoff

Radial cutoff for the coordination number
real(kind=wp), public :: directed_factor

Factor determining whether the CN is evaluated with direction if +1 the CN contribution is added equally to both partners if -1 (i.e. with the EN-dep.) it is added to one and subtracted from the other
real(kind=wp), public :: kcn

Steepness of counting function

Type-Bound Procedures

procedure, public :: add_coordination_number_derivs

Add CN derivative of an arbitrary function

  • private subroutine add_coordination_number_derivs(self, mol, trans, dEdcn, gradient, sigma)

    Arguments

    Type IntentOptional Attributes Name
    class(ncoord_type), intent(in) :: self

    Coordination number container
    type(structure_type), intent(in) :: mol

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

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

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

    Derivative of the CN with respect to the Cartesian coordinates
    real(kind=wp), intent(inout) :: sigma(:,:)

    Derivative of the CN with respect to strain deformations

procedure, public :: get_cn

Obtains lattice information and calls get_coordination number

  • private subroutine get_cn(self, mol, cn, dcndr, dcndL)

    Wrapper for CN using the CN cutoff for the lattice

    Arguments

    Type IntentOptional Attributes Name
    class(ncoord_type), intent(in) :: self

    Coordination number container
    type(structure_type), intent(in) :: mol

    Molecular structure data
    real(kind=wp), intent(out) :: cn(:)

    Error function coordination number.
    real(kind=wp), intent(out), optional :: dcndr(:,:,:)

    Derivative of the CN with respect to the Cartesian coordinates.
    real(kind=wp), intent(out), optional :: dcndL(:,:,:)

    Derivative of the CN with respect to strain deformations.

procedure, public :: get_coordination_number

Decides whether the energy or gradient is calculated

  • private subroutine get_coordination_number(self, mol, trans, cn, dcndr, dcndL)

    Geometric fractional coordination number

    Arguments

    Type IntentOptional Attributes Name
    class(ncoord_type), intent(in) :: self

    Coordination number container
    type(structure_type), intent(in) :: mol

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

    Lattice points
    real(kind=wp), intent(out) :: cn(:)

    Error function coordination number.
    real(kind=wp), intent(out), optional :: dcndr(:,:,:)

    Derivative of the CN with respect to the Cartesian coordinates.
    real(kind=wp), intent(out), optional :: dcndL(:,:,:)

    Derivative of the CN with respect to strain deformations.

procedure, public :: get_en_factor

Evaluates pairwise electronegativity factor

  • private elemental function get_en_factor(self, izp, jzp) result(en_factor)

    Evaluates pairwise electronegativity factor if non applies

    Arguments

    Type IntentOptional Attributes Name
    class(ncoord_type), intent(in) :: self

    Coordination number container
    integer, intent(in) :: izp

    Atom i index
    integer, intent(in) :: jzp

    Atom j index

    Return Value real(kind=wp)

procedure, public :: ncoord

Evaluates the CN from the specific counting function

  • private subroutine ncoord(self, mol, trans, cn)

    Arguments

    Type IntentOptional Attributes Name
    class(ncoord_type), intent(in) :: self

    Coordination number container
    type(structure_type), intent(in) :: mol

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

    Lattice points
    real(kind=wp), intent(out) :: cn(:)

    Error function coordination number.

procedure(ncoord_count), public, deferred :: ncoord_count

Evaluates the counting function (exp, dexp, erf, …)

  • elemental function ncoord_count(self, izp, jzp, r) result(count) Prototype

    Abstract counting function

    Arguments

    Type IntentOptional Attributes Name
    class(ncoord_type), intent(in) :: self

    Instance of coordination number container
    integer, intent(in) :: izp

    Atom i index
    integer, intent(in) :: jzp

    Atom j index
    real(kind=wp), intent(in) :: r

    Current distance.

    Return Value real(kind=wp)

procedure, public :: ncoord_d

Evaluates derivative of the CN from the specific counting function

  • private subroutine ncoord_d(self, mol, trans, cn, dcndr, dcndL)

    Arguments

    Type IntentOptional Attributes Name
    class(ncoord_type), intent(in) :: self

    Coordination number container
    type(structure_type), intent(in) :: mol

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

    Lattice points
    real(kind=wp), intent(out) :: cn(:)

    Error function coordination number.
    real(kind=wp), intent(out) :: dcndr(:,:,:)

    Derivative of the CN with respect to the Cartesian coordinates.
    real(kind=wp), intent(out) :: dcndL(:,:,:)

    Derivative of the CN with respect to strain deformations.

procedure(ncoord_dcount), public, deferred :: ncoord_dcount

Evaluates the derivative of the counting function (exp, dexp, erf, …)

  • elemental function ncoord_dcount(self, izp, jzp, r) result(count) Prototype

    Abstract derivative of the counting function w.r.t. the distance.

    Arguments

    Type IntentOptional Attributes Name
    class(ncoord_type), intent(in) :: self

    Instance of coordination number container
    integer, intent(in) :: izp

    Atom i index
    integer, intent(in) :: jzp

    Atom j index
    real(kind=wp), intent(in) :: r

    Current distance.

    Return Value real(kind=wp)

Source Code

   type, public, abstract :: ncoord_type
      !> Radial cutoff for the coordination number
      real(wp)  :: cutoff
      !> Steepness of counting function
      real(wp)  :: kcn 
      !> Factor determining whether the CN is evaluated with direction
      !> if +1 the CN contribution is added equally to both partners
      !> if -1 (i.e. with the EN-dep.) it is added to one and subtracted from the other
      real(wp)  :: directed_factor
      !> Cutoff for the maximum coordination number (negative value, no cutoff)
      real(wp)  :: cut = -1.0_wp
   contains
      !> Obtains lattice information and calls get_coordination number
      procedure :: get_cn
      !> Decides whether the energy or gradient is calculated
      procedure :: get_coordination_number
      !> Evaluates the CN from the specific counting function
      procedure :: ncoord
      !> Evaluates derivative of the CN from the specific counting function
      procedure :: ncoord_d
      !> Evaluates pairwise electronegativity factor
      procedure :: get_en_factor
      !> Add CN derivative of an arbitrary function
      procedure :: add_coordination_number_derivs
      !> Evaluates the counting function (exp, dexp, erf, ...)
      procedure(ncoord_count),  deferred :: ncoord_count
      !> Evaluates the derivative of the counting function (exp, dexp, erf, ...)
      procedure(ncoord_dcount), deferred :: ncoord_dcount
   end type ncoord_type