dftd4_ncoord Module

Uses

- mctc_io
- mctc_io_constants
- mctc_env

Variables

Type	Visibility	Attributes		Name		Initial
real(kind=wp),	private,	parameter	::	k4	=	4.10451_wp	Parameter for electronegativity scaling
real(kind=wp),	private,	parameter	::	k5	=	19.08857_wp	Parameter for electronegativity scaling
real(kind=wp),	private,	parameter	::	k6	=	211.28174_wp*2	Parameter for electronegativity scaling
real(kind=wp),	private,	parameter	::	kcn	=	7.5_wp	Steepness of counting function

Functions

private pure function derf_count(k, r, r0) result(count)

Derivative of the counting function w.r.t. the distance.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=wp),	intent(in)			::	k	Steepness of the counting function.
real(kind=wp),	intent(in)			::	r	Current distance.
real(kind=wp),	intent(in)			::	r0	Cutoff radius.

Return Value real(kind=wp)

private pure function erf_count(k, r, r0) result(count)

Error function counting function for coordination number contributions.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=wp),	intent(in)			::	k	Steepness of the counting function.
real(kind=wp),	intent(in)			::	r	Current distance.
real(kind=wp),	intent(in)			::	r0	Cutoff radius.

Return Value real(kind=wp)

Subroutines

public subroutine add_coordination_number_derivs(mol, trans, cutoff, rcov, en, dEdcn, gradient, sigma)

Arguments

Type	Intent	Optional	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)			::	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

public subroutine get_coordination_number(mol, trans, cutoff, rcov, en, cn, dcndr, dcndL)

Geometric fractional coordination number, supports error function counting.

Arguments

Type	Intent	Optional	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(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.

private subroutine ncoord_derf(mol, trans, cutoff, rcov, en, cn, dcndr, dcndL)

Arguments

Type	Intent	Optional	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(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.

private subroutine ncoord_erf(mol, trans, cutoff, rcov, en, cn)

Arguments

Type	Intent	Optional	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(out)			::	cn(:)	Error function coordination number.