qs_diis Namespace Reference

Apply the direct inversion in the iterative subspace (DIIS) of Pulay in the framework of an SCF iteration for convergence acceleration. More...

Functions
subroutine, public	qs_diis_b_create (diis_buffer, nbuffer, error)
	Allocates an SCF DIIS buffer.
subroutine	qs_diis_b_check_i_alloc (diis_buffer, matrix_struct, nspin, scf_section, error)
	Allocate and initialize a DIIS buffer for nao*nao parameter variables and with a buffer size of nbuffer.
subroutine, public	qs_diis_b_step (diis_buffer, mo_array, kc, sc, delta, error_max, diis_step, eps_diis, nmixing, s_matrix, scf_section, roks, error)
	Update the SCF DIIS buffer, and if appropriate does a diis step.
subroutine, public	qs_diis_b_clear (diis_buffer, error)
	clears the buffer
Variables
CHARACTER(len=*), parameter, private	moduleN = 'qs_diis'
INTEGER, save	last_diis_b_id = 0

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Detailed Description

Apply the direct inversion in the iterative subspace (DIIS) of Pulay in the framework of an SCF iteration for convergence acceleration.

Literature

• P. Pulay, Chem. Phys. Lett. 73, 393 (1980)
• P. Pulay, J. Comput. Chem. 3, 556 (1982)

History

• Changed to BLACS matrix usage (08.06.2001,MK)
• rewritten to include LSD (1st attempt) (01.2003, Joost VandeVondele)
• DIIS for ROKS (05.04.06,MK)

Author:

Matthias Krack (28.06.2000)

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Function Documentation

subroutine qs_diis::qs_diis_b_check_i_alloc	(	TYPE(qs_diis_buffer_type),pointer	diis_buffer,
		TYPE(cp_fm_struct_type),pointer	matrix_struct,
		INTEGER,intent(in)	nspin,
		TYPE(section_vals_type),pointer	scf_section,
		TYPE(cp_error_type),intent(inout)	error
	)		[private]

Allocate and initialize a DIIS buffer for nao*nao parameter variables and with a buffer size of nbuffer.

Parameters:

diis_buffer	the buffer to initialize
matrix_struct	the structure for the matrix of the buffer
error	variable to control error logging, stopping,... see module cp_error_handling

Note:

check to allocate matrixes only when needed, using a linked list?

History

• Creation (07.05.2001, Matthias Krack)
• Changed to BLACS matrix usage (08.06.2001,MK)
• DIIS for ROKS (05.04.06,MK)

Author:

Matthias Krack

Definition at line 127 of file qs_diis.f90.

References cp_fm_types::cp_fm_create(), cp_output_handling::cp_print_key_finished_output(), error, and timings::timeset().

Referenced by qs_diis_b_step().

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subroutine,public qs_diis::qs_diis_b_clear	(	TYPE(qs_diis_buffer_type),pointer	diis_buffer,
		TYPE(cp_error_type),intent(inout)	error
	)

clears the buffer

Parameters:

diis_buffer	the buffer to clear
error	variable to control error logging, stopping,... see module cp_error_handling

History

02.2003 created [fawzi]

Author:

fawzi

Definition at line 548 of file qs_diis.f90.

References timings::timeset().

Referenced by qs_scf::init_scf_loop(), and xas_methods::xas().

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subroutine,public qs_diis::qs_diis_b_create	(	TYPE(qs_diis_buffer_type),pointer	diis_buffer,
		INTEGER,intent(in)	nbuffer,
		TYPE(cp_error_type),intent(inout)	error
	)

Allocates an SCF DIIS buffer.

Parameters:

diis_buffer	the buffer to create
error	variable to control error logging, stopping,... see module cp_error_handling

History

02.2003 created [fawzi]

Author:

fawzi

Definition at line 76 of file qs_diis.f90.

References CPPostcondition, last_diis_b_id, and timings::timeset().

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subroutine,public qs_diis::qs_diis_b_step	(	TYPE(qs_diis_buffer_type),pointer	diis_buffer,
		TYPE(mo_set_p_type),dimension(:),pointer	mo_array,
		TYPE(cp_fm_p_type),dimension(:),pointer	kc,
		TYPE(cp_fm_type),pointer	sc,
		REAL(KIND=dp),intent(in)	delta,
		REAL(KIND=dp),intent(out)	error_max,
		LOGICAL,intent(out)	diis_step,
		REAL(KIND=dp),intent(in)	eps_diis,
		INTEGER,intent(in),optional	nmixing,
		TYPE(cp_dbcsr_p_type),dimension(:),optional,pointer	s_matrix,
		TYPE(section_vals_type),pointer	scf_section,
		LOGICAL,intent(in),optional	roks,
		TYPE(cp_error_type),intent(inout)	error
	)

Update the SCF DIIS buffer, and if appropriate does a diis step.

Parameters:

error

variable to control error logging, stopping,... see module cp_error_handling

History

• Creation (07.05.2001, Matthias Krack)
• Changed to BLACS matrix usage (08.06.2001, MK)
• 03.2003 rewamped [fawzi]
• Adapted for high-spin ROKS (08.04.06,MK)

Author:

Matthias Krack

Definition at line 226 of file qs_diis.f90.

References string_utilities::compress(), cp_dbcsr_operations::copy_dbcsr_to_fm(), cp_fm_basic_linalg::cp_fm_column_scale(), cp_output_handling::cp_print_key_finished_output(), mathlib::diamat_all(), error, qs_mo_types::get_mo_set(), qs_diis_b_check_i_alloc(), and timings::timeset().

Referenced by qs_scf_diagonalization::do_general_diag(), qs_scf_diagonalization::do_ot_diag(), qs_scf_diagonalization::do_roks_diag(), and qs_scf_diagonalization::do_special_diag().

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Variable Documentation

INTEGER,save qs_diis::last_diis_b_id = 0

Definition at line 57 of file qs_diis.f90.

Referenced by qs_diis_b_create().

CHARACTER(len=*),parameter,private qs_diis::moduleN = 'qs_diis'

Definition at line 56 of file qs_diis.f90.