Section MIXED

• This section allows to use any function of the energy subsystems in a mixed_env calculation as a collective variable.

• Section path: CP2K_INPUT / FORCE_EVAL / SUBSYS / COLVAR / U / MIXED

• This section cannot be repeated and cannot be optional.

• Subsections

  • none

• Keywords

  • DX
  • ENERGY_FUNCTION
  • ERROR_LIMIT
  • PARAMETERS
  • UNITS
  • VALUES
  • VARIABLES

• Keyword descriptions

  DX
  	DX <REAL>
  	Parameter used for computing the derivative with the Ridders method.
  	This optional keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-01
  	Default unit: [bohr]

  ENERGY_FUNCTION
  	ENERGY_FUNCTION (E1+E2-LOG(E1/E2))
  	Specifies the functional form of the collective variable in mathematical notation.
  	This required keyword cannot be repeated and it expects precisely one string.

  ERROR_LIMIT
  	ERROR_LIMIT <REAL>
  	Checks that the error in computing the derivative is not larger than the value set. In case prints a warning message.
  	This optional keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-12

  PARAMETERS
  	PARAMETERS A B D
  	Defines the parameters of the functional form
  	This required keyword can be repeated and it expects a list of words.

  UNITS
  	UNITS ANGSTROM EV*ANGSTROM^-1 ANGSTROM^1 K
  	Optionally, allows to define valid CP2K unit strings for each parameter value. It is assumed that the corresponding parameter value is specified in this unit.
  	This optional keyword can be repeated and it expects a list of words.

  VALUES
  	VALUES
  	Defines the values of parameter of the functional form
  	This required keyword can be repeated and it expects a list of reals.
  	Default unit: [internal_cp2k]

  VARIABLES
  	VARIABLES X
  	Defines the variables of the functional form. To allow an efficient mapping the order of the energy variables will be considered identical to the order of the force_eval in the force_eval_order list.
  	This required keyword cannot be repeated and it expects a list of words.