Section MATRIX_ITERATE

• Controls linear scaling iterative procedure on matrices: inversion, sqrti, etc. High-order Lanczos accelerates convergence provided it can estimate the eigenspectrum correctly.

• Section path: CP2K_INPUT / FORCE_EVAL / DFT / ALMO_SCF / MATRIX_ITERATE

• This section cannot be repeated.

• Subsections

  • none

• Keywords

  • EPS_LANCZOS
  • EPS_TARGET_FACTOR
  • MAX_ITER_LANCZOS
  • ORDER_LANCZOS

• Keyword descriptions

  EPS_LANCZOS
  	EPS_LANCZOS {Real}
  	Threshold for Lanczos eigenvalue estimation.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-003

  EPS_TARGET_FACTOR
  	EPS_TARGET_FACTOR {Real}
  	Multiplication factor that determines acceptable error in the iterative procedure. Acceptable error = EPS_TARGET_FACTOR * EPS_FILTER
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E+001

  MAX_ITER_LANCZOS
  	MAX_ITER_LANCZOS {Integer}
  	Maximum number of Lanczos iterations.
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 128

  ORDER_LANCZOS
  	ORDER_LANCZOS {Integer}
  	Order of the Lanczos estimator. Use 0 to turn off. Do not use 1.
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 3