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

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

• Keywords

  • SECTION_PARAMETERS
  • BISECTION
  • CELL_SHAPE
  • CELL_SIZE
  • DENSITY
  • DROP_UNUSED_ENVS
  • HELIUM_ONLY
  • INOROT
  • IROT
  • MAX_PERM_CYCLE
  • NATOMS
  • NBEADS
  • NUM_ENV
  • PERIODIC
  • POTENTIAL_FILE_NAME
  • PRESAMPLE

• 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-02
  	Default unit: [angstrom^-3]

  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.

  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.

  INOROT
  	INOROT {Integer}
  	Number of MC iterations at the same time slice(s)
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 10000

  IROT
  	IROT {Integer}
  	how often to reselect the time slice(s) to work on
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 10000

  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

  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.