Section LINK

• Specify information on the QM/MM link treatment

• Section path: CP2K_INPUT / FORCE_EVAL / QMMM / FORCE_MIXING / BUFFER_LINKS / LINK

• This section can be repeated.

• Subsections

  • ADD_MM_CHARGE
  • MOVE_MM_CHARGE

• Keywords

  • ALPHA_IMOMM
  • CORR_RADIUS
  • FIST_SCALE_FACTOR
  • LINK_TYPE
  • MM_INDEX
  • QMMM_SCALE_FACTOR
  • QM_INDEX
  • QM_KIND
  • RADIUS

• Keyword descriptions

  ALPHA_IMOMM
  	ALPHA_IMOMM {Real}
  	Specifies the scaling factor to be used for projecting the forces on the capping hydrogen in the IMOMM QM/MM link scheme to the MM atom of the link. A good guess can be derived from the bond distances of the forcefield: alpha = r_eq(QM-MM) / r_eq(QM-H).
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.38000000E+000
  	Alias names for this keyword: ALPHA

  CORR_RADIUS
  	CORR_RADIUS {Real}
  	Overwrite the specification of the correction radius only for the MM atom involved in the link.Default is to use the same correction radius as for the specified type.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [angstrom]

  FIST_SCALE_FACTOR
  	FIST_SCALE_FACTOR {Real}
  	Specifies the scaling factor for the MM charge involved in the link QM/MM. This keyword modifies the MM charge in FIST. The modified charge will be used then also for the generation of the QM/MM potential. Default 1.0 i.e. no charge rescaling of the MM atom of the QM/MM link bond.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E+000
  	Alias names for this keyword: FIST_CHARGE_SCALE, FIST_CHARGE_FACTOR, FIST_SCALE_CHARGE

  LINK_TYPE
  	LINK_TYPE {Keyword}
  	Specifies the method to use to treat the defined QM/MM link
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: IMOMM
  	List of valid keywords: GHO Use Generalized Hybrid Orbital method IMOMM Use Integrated Molecular Orbital Molecular Mechanics method PSEUDO Use a monovalent pseudo-potential
  	Alias names for this keyword: LINK, TYPE, LTYPE

  MM_INDEX
  	MM_INDEX {Integer}
  	Specifies the index of the MM atom involved in the QM/MM link, Default hydrogen.
  	This keyword cannot be repeated and it expects precisely one integer.
  	Alias names for this keyword: MM

  QMMM_SCALE_FACTOR
  	QMMM_SCALE_FACTOR {Real}
  	Specifies the scaling factor for the MM charge involved in the link QM/MM. This keyword affects only the QM/MM potential, it doesn't affect the electrostatic in the classical part of the code. Default 1.0 i.e. no charge rescaling of the MM atom of the QM/MM link bond.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E+000
  	Alias names for this keyword: QMMM_CHARGE_SCALE, QMMM_CHARGE_FACTOR, QMMM_SCALE_CHARGE

  QM_INDEX
  	QM_INDEX {Integer}
  	Specifies the index of the QM atom involved in the QM/MM link
  	This keyword cannot be repeated and it expects precisely one integer.
  	Alias names for this keyword: QM

  QM_KIND
  	QM_KIND {Word}
  	Specifies the element of the QM capping atom involved in the QM/MM link
  	This keyword cannot be repeated and it expects precisely one word.
  	Default value: H

  RADIUS
  	RADIUS {Real}
  	Overwrite the specification of the radius only for the MM atom involved in the link.Default is to use the same radius as for the specified type.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [angstrom]