Section ENFORCE_OCCUPATION

• Enforce and control a special (initial) orbital occupation. Note, this feature works only for the methods MULLIKEN and LOWDIN. It should only be used to prepare an initial configuration. An inadequate parameter choice can easily inhibit SCF convergence.

• Section path: CP2K_INPUT / FORCE_EVAL / SUBSYS / KIND / DFT_PLUS_U / ENFORCE_OCCUPATION

• This section cannot be repeated.

• Subsections

  • none

• Keywords

  • SECTION_PARAMETERS
  • EPS_SCF
  • MAX_SCF
  • NELEC
  • ORBITALS
  • SMEAR

• Keyword descriptions

  SECTION_PARAMETERS
  	&ENFORCE_OCCUPATION {Logical}
  	Controls the activation of the ENFORCE_OCCUPATION section
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.

  EPS_SCF
  	EPS_SCF {Real}
  	The occupation constraint is enforced until this threshold value for the SCF convergence criterion is reached
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E+030

  MAX_SCF
  	MAX_SCF {Integer}
  	The occupation constraint is applied for this number of initial SCF iterations
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: -1

  NELEC
  	NELEC {Real} ...
  	Number of alpha and beta electrons. An occupation (per spin) smaller than 0.5 is ignored.
  	This keyword cannot be repeated and it expects a list of reals.
  	Default value: 0.00000000E+000
  	Alias names for this keyword: N_ELECTRONS

  ORBITALS
  	ORBITALS {Integer} ...
  	Select orbitals and occupation order. An input of 1 to 2*L+1 integer values in the range -L to L defining the M values of the spherical orbitals is expected.
  	This keyword cannot be repeated and it expects a list of integers.
  	Default value: 0
  	Alias names for this keyword: M

  SMEAR
  	SMEAR {Logical}
  	The occupation constraint is applied with smearing
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.