Section FORCE_MIXING

• This section defines parameters for force-mixing based QM/MM, which actually does two conventional QM/MM calculations, on a small and a large QM regions, and combines the MM forces from one and QM forces from the other to create a complete set of forces. Energy is not conserved (although the energy from the large QM region is saved) so a proper thermostat (i.e. massive, and able to handle dissipation) must be used.

• Section path: CP2K_INPUT / FORCE_EVAL / QMMM / FORCE_MIXING

• This section cannot be repeated and can be optional.

• Subsections

  • BUFFER_LINKS
  • PRINT
  • RESTART_INFO

• Keywords

  • SECTION_PARAMETERS
  • MAX_N_QM
  • QM_EXTENDED_SEED_IS_ONLY_CORE_LIST
  • QM_KIND_ELEMENT_MAPPING
  • R_BUF
  • R_CORE
  • R_QM

• Keyword descriptions

  SECTION_PARAMETERS
  	Enables force-mixing
  	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_N_QM
  	MAX_N_QM INT
  	Maximum number of QM atoms, for detection of runaway adaptive selection.
  	This optional keyword cannot be repeated and it expects precisely one integer.
  	Default value: 300

  QM_EXTENDED_SEED_IS_ONLY_CORE_LIST
  	QM_EXTENDED_SEED_IS_ONLY_CORE_LIST <LOGICAL>
  	Makes the extended QM zone be defined hysterestically by distance from QM core list (i.e. atoms specified explicitly by user) instead of from full QM core region (specified by user + hysteretic selection + unbreakable bonds)
  	This optional keyword cannot be repeated and it expects precisely one logical.
  	Default value: .FALSE.

  QM_KIND_ELEMENT_MAPPING
  	QM_KIND_ELEMENT_MAPPING {EL} {QM_KIND}
  	Mapping from elements to QM_KINDs for adaptivity
  	This required keyword can be repeated and it expects precisely 2 words.

  R_BUF
  	R_BUF <REAL> <REAL>
  	Specify the inner and outer radii of buffer region. All atoms within this distance (hysteretically) of any QM atoms will be buffer atoms in the force-mixing calculation.
  	This optional keyword cannot be repeated and it expects precisely 2 reals.
  	Default values: 5.00000000E-01 1.00000000E+00
  	Default unit: [angstrom]

  R_CORE
  	R_CORE <REAL> <REAL>
  	Specify the inner and outer radii of core QM region. All atoms within this distance (hysteretically) of any atoms listed in ATOM_INDEX will be core QM atoms in the force-mixing calculation.
  	This optional keyword cannot be repeated and it expects precisely 2 reals.
  	Default values: 0.00000000E+00 0.00000000E+00
  	Default unit: [angstrom]

  R_QM
  	R_QM <REAL> <REAL>
  	Specify the inner and outer radii of extended QM region. All atoms within this distance (hysteretically) of any atoms listed in ATOM_INDEX will be QM atoms in the force-mixing calculation.
  	This optional keyword cannot be repeated and it expects precisely 2 reals.
  	Default values: 5.00000000E-01 1.00000000E+00
  	Default unit: [angstrom]