Section CG

• Provides parameters to tune the conjugate gradient optimization

• Section path: CP2K_INPUT / MOTION / CELL_OPT / CG

• This section cannot be repeated and can be optional.

• Subsections

  • LINE_SEARCH

• Keywords

  • FLETCHER_REEVES
  • MAX_STEEP_STEPS
  • RESTART_LIMIT

• Keyword descriptions

  FLETCHER_REEVES
  	FLETCHER-REEVES
  	Uses FLETCHER-REEVES instead of POLAK-RIBIERE when using Conjugate Gradients
  	This optional keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.

  MAX_STEEP_STEPS
  	MAX_STEEP_STEPS {INTEGER}
  	Maximum number of steepest descent steps before starting the conjugate gradients optimization.
  	This optional keyword cannot be repeated and it expects precisely one integer.
  	Default value: 0

  RESTART_LIMIT
  	RESTART_LIMIT {REAL}
  	Cosine of the angle between two consecutive searching directions. If the angle during a CG optimization is less than the one corresponding to to the RESTART_LIMIT the CG is reset and one step of steepest descent is performed.
  	This optional keyword cannot be repeated and it expects precisely one real.
  	Default value: 9.00000000E-01