Section IMAGE_CHARGE

• Inclusion of polarization effects within the image charge approach for systems where QM molecules are physisorbed on e.g. metal surfaces described by MM. QM box size has to be equal to MM box size.

• Section path: CP2K_INPUT / FORCE_EVAL / QMMM / IMAGE_CHARGE

• This section cannot be repeated.

• This section cites the following reference: [Golze2013]

• Subsections

  • ERI_MME

• Keywords

  • DETERM_COEFF
  • EXT_POTENTIAL
  • IMAGE_MATRIX_METHOD
  • IMAGE_RESTART_FILE_NAME
  • MM_ATOM_LIST
  • RESTART_IMAGE_MATRIX
  • WIDTH

• Keyword descriptions

  DETERM_COEFF
  	DETERM_COEFF {Keyword}
  	Specifies how the coefficients are determined.
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: CALC_MATRIX
  	List of valid keywords: CALC_MATRIX Calculates image matrix and solves linear set of equations ITERATIVE Uses an iterative scheme to calculate the coefficients

  EXT_POTENTIAL
  	EXT_POTENTIAL {Real}
  	External potential applied to the metal electrode
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+000
  	Default unit: [volt]

  IMAGE_MATRIX_METHOD
  	IMAGE_MATRIX_METHOD {Keyword}
  	Method for calculating the image matrix. The MME method is much faster than GPW s.t. the overhead of the IC approach compared to standard QM/MM becomes negligible in total computation time. Note that MME is an approximative method that has limited accuracy in the current implementation.
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: GPW
  	List of valid keywords: GPW Uses Gaussian Plane Wave method [Golze2013] MME Uses MiniMax-Ewald method (ERI_MME subsection)

  IMAGE_RESTART_FILE_NAME
  	IMAGE_RESTART_FILE_NAME {String}
  	File name where to read the image matrix used as preconditioner in the iterative scheme
  	This keyword cannot be repeated and it expects precisely one string.

  MM_ATOM_LIST
  	MM_ATOM_LIST {Integer} ... or a range {Integer}..{Integer}
  	List of MM atoms carrying an induced Gaussian charge. If this keyword is not given, all MM atoms will carry an image charge.
  	This keyword can be repeated and it expects a list of integers.

  RESTART_IMAGE_MATRIX
  	RESTART_IMAGE_MATRIX {Logical}
  	Restart the image matrix. Useful when calculating coefficients iteratively (the image matrix is used as preconditioner in that case)
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.

  WIDTH
  	WIDTH {Real}
  	Specifies the value of the width of the (induced) Gaussian charge distribution carried by each MM atom.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 3.00000000E+000
  	Default unit: [angstrom^-2]