Section OUTER_SCF

• parameters controlling the outer SCF loop

• Section path: CP2K_INPUT / FORCE_EVAL / DFT / SCF / OUTER_SCF

• This section cannot be repeated and can be optional.

• Subsections

  • none

• Keywords

  • SECTION_PARAMETERS
  • BISECT_TRUST_COUNT
  • DIIS_BUFFER_LENGTH
  • EPS_SCF
  • EXTRAPOLATION_ORDER
  • MAX_SCF
  • OPTIMIZER
  • STEP_SIZE
  • TYPE

• Keyword descriptions

  SECTION_PARAMETERS
  	&OUTER_SCF ON
  	controls the activation of the outer SCF loop
  	This optional keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.

  BISECT_TRUST_COUNT
  	BISECT_TRUST_COUNT 5
  	Maximum number of times the same point will be used in bisection, a small number guards against the effect of wrongly converged states.
  	This optional keyword cannot be repeated and it expects precisely one integer.
  	Default value: 10

  DIIS_BUFFER_LENGTH
  	DIIS_BUFFER_LENGTH 5
  	Maximum number of DIIS vectors used
  	This optional keyword cannot be repeated and it expects precisely one integer.
  	Default value: 3

  EPS_SCF
  	EPS_SCF 1.0E-6
  	The target gradient of the outer scf variables. Notice that the EPS_SCF of the inner loop also determines the value that can be reached in the outer loop, typically EPS_SCF of the outer loop must be smaller than EPS_SCF of the inner loop.
  	This optional keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-05

  EXTRAPOLATION_ORDER
  	EXTRAPOLATION_ORDER 5
  	Number of past states used in the extrapolation of the variables during e.g. MD
  	This optional keyword cannot be repeated and it expects precisely one integer.
  	Default value: 3

  MAX_SCF
  	MAX_SCF 20
  	The maximum number of outer loops
  	This optional keyword cannot be repeated and it expects precisely one integer.
  	Default value: 50

  OPTIMIZER
  	OPTIMIZER SD
  	Method used to bring the outer loop to a stationary point
  	This optional keyword cannot be repeated and it expects precisely one keyword.
  	Default value: NONE
  	List of valid keywords: BISECT Bisection on the gradient, useful for difficult one dimensional cases DIIS Uses a Direct Inversion in the Iterative Subspace method NONE Do nothing, useful only with the none type SD Takes steps in the direction of the gradient, multiplied by step_size

  STEP_SIZE
  	STEP_SIZE -1.0
  	The initial step_size used in the optimizer (currently steepest descent).Note that in cases where a sadle point is sought for (DDAPC_CONSTRAINT), this can be negative
  	This optional keyword cannot be repeated and it expects precisely one real.
  	Default value: 5.00000000E-01

  TYPE
  	TYPE DDAPC_CONSTRAINT
  	Specifies which kind of outer SCF should be employed
  	This optional keyword cannot be repeated and it expects precisely one keyword.
  	Default value: NONE
  	List of valid keywords: BECKE_CONSTRAINT Enforce a constraint on the Becke weight population,requires the corresponding section DDAPC_CONSTRAINT Enforce a constraint on the DDAPC, requires the corresponding section NONE Do nothing in the outer loop, useful for resetting the inner loop, S2_CONSTRAINT Enforce a constraint on the S2, requires the corresponding section SCP Enforce outer loop optimization for SCP, requires the corresponding metod (-DFT or -NDDO)