# METADYN

References: VandenEijnden2006

This section sets parameters to set up a calculation of metadynamics. [Edit on GitHub]

Subsections

- EXT_LAGRANGE_FS
- EXT_LAGRANGE_SS
- EXT_LAGRANGE_SS0
- EXT_LAGRANGE_VVP
- METAVAR
- MULTIPLE_WALKERS
- PRINT
- SPAWNED_HILLS_HEIGHT
- SPAWNED_HILLS_INVDT
- SPAWNED_HILLS_POS
- SPAWNED_HILLS_SCALE

## Keywords

- COLVAR_AVG_TEMPERATURE_RESTART

- DELTA_T

- DO_HILLS

- HILL_TAIL_CUTOFF

- LAGRANGE

- LANGEVIN

- MIN_DISP

- MIN_NT_HILLS

- NHILLS_START_VAL

- NT_HILLS

- OLD_HILL_NUMBER

- OLD_HILL_STEP

- PLUMED_INPUT_FILE

- P_EXPONENT

- Q_EXPONENT

- SLOW_GROWTH

- STEP_START_VAL

- TAMCSTEPS

- TEMPERATURE

- TEMP_TOL

- TIMESTEP

- USE_PLUMED

- WELL_TEMPERED

- WTGAMMA

- WW

## Keyword descriptions

COLVAR_AVG_TEMPERATURE_RESTART: real = 0.00000000E+000

  Usage: COLVAR_AVG_TEMPERATURE_RESTART 0.0

  COLVAR average temperature. Only for restarting purposes. [Edit on GitHub]

DELTA_T: real = 0.00000000E+000 [K]

  Usage: DELTA_T <REAL>

  If Well-tempered metaD is used, the temperature parameter must be specified. [Edit on GitHub]

DO_HILLS: logical = F

  Lone keyword: `T`

  Usage: DO_HILLS

  This keyword enables the spawning of the hills. Default .FALSE. [Edit on GitHub]

HILL_TAIL_CUTOFF: real = -1.00000000E+000

  Usage: HILL_TAIL_CUTOFF <REAL>

  By setting this variable larger than 0 the tail of the Gaussian hill is damped to zero faster. The Gaussian function is multiplied by a cutoff function that becomes active at |x-X0|>HILL_TAIL_CUTOFFSCALE, where X0 is the location of the Gaussian and SCALE is the width of the Gaussian. For more than one METAVAR X0 and SCALE are METAVAR-dependent. (1-(|x-X0|/HILL_TAIL_CUTOFFSCALE)^P_EXP)/(1-(|x-X0|/HILL_TAIL_CUTOFF*SCALE)^Q_EXP) [Edit on GitHub]

LAGRANGE: logical = F

  Lone keyword: `T`

  Usage: LAGRANGE

  Specifies whether an extended-lagrangian should be used. Default .FALSE. [Edit on GitHub]

LANGEVIN: logical = F

  Lone keyword: `T`

  Usage: LANGEVIN {logical}

  References: VandenEijnden2006

  If a Lagrangian scheme is used the eq. motion of the COLVARS are integrated with a LANGEVIN scheme. [Edit on GitHub]

MIN_DISP: real = -1.00000000E+000

  Usage: MIN_DISP <REAL>

  Minimum displacement between hills before placing a new hill. [Edit on GitHub]

MIN_NT_HILLS: integer = 1

  Usage: MIN_NT_HILLS {integer}

  Specify the minimum MD step interval between spawning two hills. If specified, it must be >= than NT_HILLS. In case MIN_DISP is used, if MIN_DISP is satisfied before MIN_NT_HILLS MD steps have been performed, the MD will continue without any spawning until MIN_NT_HILLS is reached. The default value has the net effect of skipping this check. [Edit on GitHub]

NHILLS_START_VAL: integer = 0

  Usage: nhills_start_val <integer>

  The starting value of previously spawned hills [Edit on GitHub]

NT_HILLS: integer = 30

  Usage: NT_HILLS {integer}

  Mentions: ⭐QM/MM with Built-in Force Field

  Specify the maximum MD step interval between spawning two hills. When negative, no new hills are spawned and only the hills read from SPAWNED_HILLS_* are in effect. The latter is useful when one wants to add a custom constant bias potential. [Edit on GitHub]

OLD_HILL_NUMBER: integer = 0

  Usage: OLD_HILL_NUMBER <INT>

  Index of the last hill spawned for this walker.Needed to calculate MIN_DISP [Edit on GitHub]

OLD_HILL_STEP: integer = 0

  Usage: OLD_HILL_STEP <INT>

  Timestep of the last hill spawned for this walker.Needed to calculate MIN_DISP [Edit on GitHub]

PLUMED_INPUT_FILE: string = ./plumed.dat

  Usage: PLUMED_INPUT_FILE ./FILENAME

  Specify the file name of the external plumed input file [Edit on GitHub]

P_EXPONENT: integer = 8

  Usage: P_EXPONENT <INT>

  Exponent at the numerator of the cutoff function to damp the tail of the Gaussian. [Edit on GitHub]

Q_EXPONENT: integer = 20

  Usage: Q_EXPONENT <INT>

  Exponent at the denominator of the cutoff function to damp the tail of the Gaussian. [Edit on GitHub]

SLOW_GROWTH: logical = F

  Lone keyword: `T`

  Usage: SLOW_GROWTH {logical}

  Let the last hill grow slowly over NT_HILLS. [Edit on GitHub]

STEP_START_VAL: integer = 0

  Usage: step_start_val <integer>

  The starting step value for metadynamics [Edit on GitHub]

TAMCSTEPS: integer = 1

  Usage: TAMCSteps <integer>

  Number of sampling points for z [Edit on GitHub]

TEMPERATURE: real = 0.00000000E+000 [K]

  Usage: TEMPERATURE <REAL>

  If a Lagrangian scheme is used the temperature for the collective variables is specified. [Edit on GitHub]

TEMP_TOL: real = 0.00000000E+000 [K]

  Usage: TEMP_TOL <REAL>

  If a Lagrangian scheme is used the temperature tolerance for the collective variables is specified. [Edit on GitHub]

TIMESTEP: real = 5.00000000E-001 [fs]

  Usage: timestep <real>

  The length of an integration step for colvars (TAMC only) [Edit on GitHub]

USE_PLUMED: logical = F

  Lone keyword: `T`

  Usage: USE_PLUMED .FALSE./.TRUE.

  Specify whether to use plumed as an external metadynamics driver. [Edit on GitHub]

WELL_TEMPERED: logical = F

  Lone keyword: `T`

  Usage: WELL_TEMPERED

  References: Barducci2008

  This keyword enables Well-tempered metadynamics. Default .FALSE. [Edit on GitHub]

WTGAMMA: real = 0.00000000E+000

  Usage: WTGAMMA <REAL>

  If Well-tempered metaD is used, the gamma parameter must be specified if not DELTA_T. [Edit on GitHub]

WW: real = 1.00000000E-001 [hartree]

  Usage: WW <REAL>

  Mentions: ⭐QM/MM with Built-in Force Field

  Specifies the height of the gaussian to spawn. Default 0.1 . [Edit on GitHub]