Action: EFFECTIVE_ENERGY_DRIFT

Module	generic
Description	Usage
Print the effective energy drift

Further details and examples

Print the effective energy drift

The method that is used to calculate the effective energy drift here is described in the paper in the bibliography.

Examples

This input is to monitor the effective energy drift for a metadynamics simulation on the Debye-Huckel energy. Since this variable is very expensive, it could be conveniently computed every second step.

Click on the labels of the actions for more information on what each action computes

dhThe DHENERGY action with label dh calculates the following quantities:
 Quantity   
 Type   
 Description  
dh
scalar
the value of the DHENERGY: DHENERGYCalculate Debye-Huckel interaction energy between the atoms in GROUPA and GROUPB. More details GROUPAFirst list of atoms=1-10 GROUPBSecond list of atoms (if empty, N*(N-1)/2 pairs in GROUPA are counted)=11-20 EPSILON Dielectric constant of solvent=80.0 I Ionic strength (M)=0.1 TEMP Simulation temperature (K)=300.0
METADUsed to performed metadynamics on one or more collective variables. More details ARGthe labels of the scalars on which the bias will act=dh HEIGHTthe heights of the Gaussian hills=0.5 SIGMAthe widths of the Gaussian hills=0.1 PACEthe frequency for hill addition=500 STRIDEthe frequency with which the forces due to the bias should be calculated=2
The METAD action with label  calculates the following quantities:
 Quantity   
 Description  
.bias
the instantaneous value of the bias potentialEFFECTIVE_ENERGY_DRIFTPrint the effective energy drift More details PRINT_STRIDEfrequency to which output the effective energy drift on FILE=100 FILEfile on which to output the effective energy drift=eff

This exampls shows how to monitor if a restraint is too stiff

Click on the labels of the actions for more information on what each action computes

dThe DISTANCE action with label d calculates the following quantities:
 Quantity   
 Type   
 Description  
d
scalar
the DISTANCE between this pair of atoms: DISTANCECalculate the distance/s between pairs of atoms. More details ATOMSthe pair of atom that we are calculating the distance between=10,20
RESTRAINTAdds harmonic and/or linear restraints on one or more variables. More details ARGthe values the harmonic restraint acts upon=d KAPPA specifies that the restraint is harmonic and what the values of the force constants on each of the variables are=100000 ATthe position of the restraint=0.6
The RESTRAINT action with label  calculates the following quantities:
 Quantity   
 Description  
.bias
the instantaneous value of the bias potential
.force2
the instantaneous value of the squared force due to this bias potentialEFFECTIVE_ENERGY_DRIFTPrint the effective energy drift More details PRINT_STRIDEfrequency to which output the effective energy drift on FILE=100 FILEfile on which to output the effective energy drift=eff

References

More information about how this action can be used is available in the following articles: - M. J. Ferrarotti, S. Bottaro, A. Pérez-Villa, G. Bussi, Accurate Multiple Time Step in Biased Molecular Simulations. Journal of Chemical Theory and Computation. 11, 139–146 (2014)

Syntax

The following table describes the keywords and options that can be used with this action