Section HELIUM

• The section that controls optional helium solvent environment (highly experimental, not for general use yet)

• Section path: CP2K_INPUT / MOTION / PINT / HELIUM

• This section cannot be repeated.

• Subsections

  • AVERAGES
  • COORD
  • FORCE
  • M-SAMPLING
  • PERM
  • PRINT
  • RDF
  • RHO
  • RNG_STATE

• Keywords

  • SECTION_PARAMETERS
  • BISECTION
  • CELL_SHAPE
  • CELL_SIZE
  • DENSITY
  • DROPLET_RADIUS
  • DROP_UNUSED_ENVS
  • GET_FORCES
  • HELIUM_ONLY
  • INTERACTION_POT_SCAN
  • MAX_PERM_CYCLE
  • NATOMS
  • NBEADS
  • NUM_ENV
  • N_INNER
  • N_OUTER
  • PERIODIC
  • POTENTIAL_FILE_NAME
  • PRESAMPLE
  • SAMPLING_METHOD
  • SOLUTE_INTERACTION

• Keyword descriptions

  SECTION_PARAMETERS
  	&HELIUM {Logical}
  	Whether or not to actually use this section
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.

  BISECTION
  	BISECTION {Integer}
  	how many time slices to change at once (+1). Must be a power of 2 currently
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 8

  CELL_SHAPE
  	CELL_SHAPE {Keyword}
  	PBC unit cell shape for helium
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: CUBE
  	List of valid keywords: CUBE Without description, yet. OCTAHEDRON Without description, yet.

  CELL_SIZE
  	CELL_SIZE {Real}
  	PBC unit cell size (NOTE 1: density, number of atoms and volume are interdependent - give only two of them; NOTE 2: for small cell sizes specify NATOMS instead)
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [angstrom]

  DENSITY
  	DENSITY {Real}
  	trial density of helium for determining the helium box size
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 2.18600000E-002
  	Default unit: [angstrom^-3]

  DROPLET_RADIUS
  	DROPLET_RADIUS {Real}
  	Reject a move if any of the new positions does not lie within this range from the center of gravity
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 9.51298235E+307
  	Default unit: [angstrom]

  DROP_UNUSED_ENVS
  	DROP_UNUSED_ENVS {Logical}
  	Drop He environments if N_restart > N_runtime (Warning: this will cause data loss in the restart file!)
  	This keyword cannot be repeated and it expects precisely one logical.
  	Default value: .FALSE.

  GET_FORCES
  	GET_FORCES {Keyword}
  	Get average MC forces or last MC forces to propagate MD
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: AVERAGE
  	List of valid keywords: AVERAGE Without description, yet. LAST Without description, yet.

  HELIUM_ONLY
  	HELIUM_ONLY {Logical}
  	Simulate helium solvent only, disregard solute entirely
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.

  INTERACTION_POT_SCAN
  	INTERACTION_POT_SCAN {Logical}
  	Scan solute-helium interaction potential, cubefile parameters set in subsection RHO
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.

  MAX_PERM_CYCLE
  	MAX_PERM_CYCLE {Integer}
  	how large cyclic permutations to try
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 6

  NATOMS
  	NATOMS {Integer}
  	Number of helium atoms
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 64

  NBEADS
  	NBEADS {Integer}
  	Number of helium path integral beads
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 25

  NUM_ENV
  	NUM_ENV {Integer}
  	Number of independent helium environments (only for restarts, do not set explicitly)
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 1

  N_INNER
  	N_INNER {Integer}
  	Number of MC iterations at the same time slice(s) (number of inner MC loop iterations)
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 6600
  	Alias names for this keyword: INOROT

  N_OUTER
  	N_OUTER {Integer}
  	how often to reselect the time slice(s) to work on (number of outer MC loop iterations)
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 300
  	Alias names for this keyword: IROT

  PERIODIC
  	PERIODIC {Logical}
  	Use periodic boundary conditions for helium
  	This keyword cannot be repeated and it expects precisely one logical.
  	Default value: .FALSE.

  POTENTIAL_FILE_NAME
  	POTENTIAL_FILE_NAME {String}
  	Name of the Helium interaction potential file
  	This keyword cannot be repeated and it expects precisely one string.
  	Default value: HELIUM.POT

  PRESAMPLE
  	PRESAMPLE {Logical}
  	Presample He coordinates before first PIMD step
  	This keyword cannot be repeated and it expects precisely one logical.
  	Default value: .FALSE.

  SAMPLING_METHOD
  	SAMPLING_METHOD {Keyword}
  	Choose between Ceperley or other not implemented algorithms
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: CEPERLEY
  	List of valid keywords: CEPERLEY Without description, yet.

  SOLUTE_INTERACTION
  	SOLUTE_INTERACTION {Keyword}
  	Interaction potential between helium and the solute
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: NONE
  	List of valid keywords: MWATER Test interaction with wrong Water NONE No interaction with solute