3-center integrals machinery for the XAS_TDP method More...

Functions/Subroutines
subroutine, public	create_pqx_tensor (pq_x, ab_nl, ac_nl, matrix_dist, blk_size_1, blk_size_2, blk_size_3, only_bc_same_center)
	Prepares a tensor to hold 3-center integrals (pq\|X), where p,q are distributed according to the given 2d dbcsr distribution of the given . The third dimension of the tensor is iteslf not distributed (i.e. the t_pgrid's third dimension has size 1). The blocks are reserved according to the neighbor lists.

subroutine, public	fill_pqx_tensor (pq_x, ab_nl, ac_nl, basis_set_list_a, basis_set_list_b, basis_set_list_c, potential_parameter, qs_env, only_bc_same_center, eps_screen)
	Fills the given 3 dimensional (pq\|X) tensor with integrals.

subroutine, public	build_xas_tdp_ovlp_nl (ab_list, basis_a, basis_b, qs_env, excited_atoms, ext_dist2d)
	Builds a neighbor lists set for overlaping 2-center S_ab, where b is restricted on a a given list of atoms. Used for Coulomb RI where (aI\|P) = sum_b C_bI (ab\|P), where contraction coeff C_bI is assumed to be non-zero only on excited atoms.

subroutine, public	build_xas_tdp_3c_nl (ac_list, basis_a, basis_c, op_type, qs_env, excited_atoms, x_range, ext_dist2d)
	Builds a neighbor lists set taylored for 3-center integral within XAS TDP, such that only excited atoms are taken into account for the list_c.

subroutine, public	get_opt_3c_dist2d (opt_3c_dist2d, ab_list, ac_list, basis_set_a, basis_set_b, basis_set_c, qs_env, only_bc_same_center)
	Returns an optimized distribution_2d for the given neighbor lists based on an evaluation of the cost of the corresponding 3-center integrals.

subroutine, public	compute_ri_3c_exchange (ex_atoms, xas_tdp_env, xas_tdp_control, qs_env)
	Computes the RI exchange 3-center integrals (ab\|c), where c is from the RI_XAS basis and centered on excited atoms and kind. The operator used is that of the RI metric.

subroutine, public	compute_ri_3c_coulomb (xas_tdp_env, qs_env)
	Computes the RI Coulomb 3-center integrals (ab\|c), where c is from the RI_XAS basis and centered on the excited atoms of xas_tdp_env.

subroutine, public	compute_ri_exchange2_int (ex_kind, xas_tdp_env, xas_tdp_control, qs_env)
	Computes the two-center Exchange integral needed for the RI in kernel calculation. Stores the integrals in the xas_tdp_env as global (small) arrays. Does that for a given excited kind. The quantity stored is M^-1 (P\|Q) M^-1, where M is the RI metric. If the metric is the same as the exchange potential, then we end up with the V-approximation (P\|Q)^-1 By default (if no metric), the ri_m_potential is a copy of the x_potential.

subroutine, public	compute_ri_coulomb2_int (ex_kind, xas_tdp_env, xas_tdp_control, qs_env)
	Computes the two-center Coulomb integral needed for the RI in kernel calculation. Stores the integrals (P\|Q)^-1 in the xas_tdp_env as global (small) arrays. Does that for a given excited kind.

Detailed Description

3-center integrals machinery for the XAS_TDP method

Author: A. Bussy (03.2020)

Function/Subroutine Documentation

◆ create_pqx_tensor()

subroutine, public xas_tdp_integrals::create_pqx_tensor	(	type(dbt_type), intent(out)	pq_x,
		type(neighbor_list_set_p_type), dimension(:), pointer	ab_nl,
		type(neighbor_list_set_p_type), dimension(:), pointer	ac_nl,
		type(dbcsr_distribution_type), intent(in)	matrix_dist,
		integer, dimension(:), intent(in)	blk_size_1,
		integer, dimension(:), intent(in)	blk_size_2,
		integer, dimension(:), intent(in)	blk_size_3,
		logical, intent(in), optional	only_bc_same_center
	)

Prepares a tensor to hold 3-center integrals (pq|X), where p,q are distributed according to the given 2d dbcsr distribution of the given . The third dimension of the tensor is iteslf not distributed (i.e. the t_pgrid's third dimension has size 1). The blocks are reserved according to the neighbor lists.

Parameters

pq_X	the tensor to store the integrals
ab_nl	the 1st and 2nd center neighbor list
ac_nl	the 1st and 3rd center neighbor list
matrix_dist	...
blk_size_1	the block size in the first dimension
blk_size_2	the block size in the second dimension
blk_size_3	the block size in the third dimension
only_bc_same_center	only keep block if, for the corresponding integral (ab\|c), b and c share the same center, i.e. r_bc = 0.0

Definition at line 126 of file xas_tdp_integrals.F.

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◆ fill_pqx_tensor()

subroutine, public xas_tdp_integrals::fill_pqx_tensor	(	type(dbt_type)	pq_x,
		type(neighbor_list_set_p_type), dimension(:), pointer	ab_nl,
		type(neighbor_list_set_p_type), dimension(:), pointer	ac_nl,
		type(gto_basis_set_p_type), dimension(:), pointer	basis_set_list_a,
		type(gto_basis_set_p_type), dimension(:), pointer	basis_set_list_b,
		type(gto_basis_set_p_type), dimension(:), pointer	basis_set_list_c,
		type(libint_potential_type)	potential_parameter,
		type(qs_environment_type), pointer	qs_env,
		logical, intent(in), optional	only_bc_same_center,
		real(dp), intent(in), optional	eps_screen
	)

Fills the given 3 dimensional (pq|X) tensor with integrals.

Parameters

pq_X	the tensor to fill
ab_nl	the neighbor list for the first 2 centers
ac_nl	the neighbor list for the first and third centers
basis_set_list_a	basis sets for first center
basis_set_list_b	basis sets for second center
basis_set_list_c	basis sets for third center
potential_parameter	the operator for the integrals
qs_env	...
only_bc_same_center	same as in create_pqX_tensor
eps_screen	threshold for possible screening

Note: The following indices are happily mixed within this routine: First center i,a,p Second center: j,b,q Third center: k,c,X

Definition at line 274 of file xas_tdp_integrals.F.

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◆ build_xas_tdp_ovlp_nl()

subroutine, public xas_tdp_integrals::build_xas_tdp_ovlp_nl	(	type(neighbor_list_set_p_type), dimension(:), pointer	ab_list,
		type(gto_basis_set_p_type), dimension(:), pointer	basis_a,
		type(gto_basis_set_p_type), dimension(:), pointer	basis_b,
		type(qs_environment_type), pointer	qs_env,
		integer, dimension(:), intent(in), optional	excited_atoms,
		type(distribution_2d_type), optional, pointer	ext_dist2d
	)

Builds a neighbor lists set for overlaping 2-center S_ab, where b is restricted on a a given list of atoms. Used for Coulomb RI where (aI|P) = sum_b C_bI (ab|P), where contraction coeff C_bI is assumed to be non-zero only on excited atoms.

Parameters

ab_list	the neighbor list
basis_a	basis set list for atom a
basis_b	basis set list for atom b
qs_env	...
excited_atoms	the indices of the excited atoms on which b is centered
ext_dist2d	use an external distribution2d

Definition at line 650 of file xas_tdp_integrals.F.

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◆ build_xas_tdp_3c_nl()

subroutine, public xas_tdp_integrals::build_xas_tdp_3c_nl	(	type(neighbor_list_set_p_type), dimension(:), pointer	ac_list,
		type(gto_basis_set_p_type), dimension(:), pointer	basis_a,
		type(gto_basis_set_p_type), dimension(:), pointer	basis_c,
		integer, intent(in)	op_type,
		type(qs_environment_type), pointer	qs_env,
		integer, dimension(:), intent(in), optional	excited_atoms,
		real(dp), intent(in), optional	x_range,
		type(distribution_2d_type), optional, pointer	ext_dist2d
	)

Builds a neighbor lists set taylored for 3-center integral within XAS TDP, such that only excited atoms are taken into account for the list_c.

Parameters

ac_list	the neighbor list ready for 3-center integrals
basis_a	basis set list for atom a
basis_c	basis set list for atom c
op_type	to indicate whther the list should be built with overlap, Coulomb or else in mind
qs_env	...
excited_atoms	the indices of the excited atoms to consider (if not given, all atoms are taken)
x_range	in case some truncated/screened operator is used, gives its range
ext_dist2d	external distribution_2d to be used

Note: Based on setup_neighbor_list with added features

Definition at line 749 of file xas_tdp_integrals.F.

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◆ get_opt_3c_dist2d()

subroutine, public xas_tdp_integrals::get_opt_3c_dist2d	(	type(distribution_2d_type), pointer	opt_3c_dist2d,
		type(neighbor_list_set_p_type), dimension(:), pointer	ab_list,
		type(neighbor_list_set_p_type), dimension(:), pointer	ac_list,
		type(gto_basis_set_p_type), dimension(:), pointer	basis_set_a,
		type(gto_basis_set_p_type), dimension(:), pointer	basis_set_b,
		type(gto_basis_set_p_type), dimension(:), pointer	basis_set_c,
		type(qs_environment_type), pointer	qs_env,
		logical, intent(in), optional	only_bc_same_center
	)

Returns an optimized distribution_2d for the given neighbor lists based on an evaluation of the cost of the corresponding 3-center integrals.

Parameters

opt_3c_dist2d	the optimized distribution_2d
ab_list	...
ac_list	...
basis_set_a	...
basis_set_b	...
basis_set_c	...
qs_env	...
only_bc_same_center	...

Definition at line 879 of file xas_tdp_integrals.F.

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◆ compute_ri_3c_exchange()

subroutine, public xas_tdp_integrals::compute_ri_3c_exchange	(	integer, dimension(:), intent(in)	ex_atoms,
		type(xas_tdp_env_type), pointer	xas_tdp_env,
		type(xas_tdp_control_type), pointer	xas_tdp_control,
		type(qs_environment_type), pointer	qs_env
	)

Computes the RI exchange 3-center integrals (ab|c), where c is from the RI_XAS basis and centered on excited atoms and kind. The operator used is that of the RI metric.

Parameters

ex_atoms	excited atoms on which the third center is located
xas_tdp_env	...
xas_tdp_control	...
qs_env	...

Note: This routine is called once for each excited atom. Because there are many different a,b pairs involved, load balance is ok. This allows memory saving

Definition at line 1044 of file xas_tdp_integrals.F.

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◆ compute_ri_3c_coulomb()

subroutine, public xas_tdp_integrals::compute_ri_3c_coulomb	(	type(xas_tdp_env_type), pointer	xas_tdp_env,
		type(qs_environment_type), pointer	qs_env
	)

Computes the RI Coulomb 3-center integrals (ab|c), where c is from the RI_XAS basis and centered on the excited atoms of xas_tdp_env.

Parameters

xas_tdp_env	...
qs_env	...

Note: The ri_3c_coul tensor of xas_tdp_env is defined and allocated here. Only computed once for the whole system (for optimized load balance). Ok because not too much memory needed

Definition at line 1131 of file xas_tdp_integrals.F.

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◆ compute_ri_exchange2_int()

subroutine, public xas_tdp_integrals::compute_ri_exchange2_int	(	integer, intent(in)	ex_kind,
		type(xas_tdp_env_type), pointer	xas_tdp_env,
		type(xas_tdp_control_type), pointer	xas_tdp_control,
		type(qs_environment_type), pointer	qs_env
	)

Computes the two-center Exchange integral needed for the RI in kernel calculation. Stores the integrals in the xas_tdp_env as global (small) arrays. Does that for a given excited kind. The quantity stored is M^-1 (P|Q) M^-1, where M is the RI metric. If the metric is the same as the exchange potential, then we end up with the V-approximation (P|Q)^-1 By default (if no metric), the ri_m_potential is a copy of the x_potential.

Parameters

ex_kind	...
xas_tdp_env	...
xas_tdp_control	...
qs_env	...

Note: Computes all these integrals in non-PBCs as we assume that the range is short enough that atoms do not exchange with their periodic images

Definition at line 1226 of file xas_tdp_integrals.F.

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◆ compute_ri_coulomb2_int()

subroutine, public xas_tdp_integrals::compute_ri_coulomb2_int	(	integer, intent(in)	ex_kind,
		type(xas_tdp_env_type), pointer	xas_tdp_env,
		type(xas_tdp_control_type), pointer	xas_tdp_control,
		type(qs_environment_type), pointer	qs_env
	)

Computes the two-center Coulomb integral needed for the RI in kernel calculation. Stores the integrals (P|Q)^-1 in the xas_tdp_env as global (small) arrays. Does that for a given excited kind.

Parameters

ex_kind	...
xas_tdp_env	...
xas_tdp_control	...
qs_env	...

Definition at line 1385 of file xas_tdp_integrals.F.

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Functions/Subroutines

Detailed Description

Function/Subroutine Documentation

◆ create_pqx_tensor()

◆ fill_pqx_tensor()

◆ build_xas_tdp_ovlp_nl()

◆ build_xas_tdp_3c_nl()

◆ get_opt_3c_dist2d()

◆ compute_ri_3c_exchange()

◆ compute_ri_3c_coulomb()

◆ compute_ri_exchange2_int()

◆ compute_ri_coulomb2_int()