Action: ENERGY

Module	colvar
Description	Usage
Calculate the total potential energy of the simulation box.

Further details and examples

Calculate the total potential energy of the simulation box.

As is explained in the papers in the bibliography the potential energy can be biased with umbrella sampling. To print the potential energy from PLUMED you can use an input similar to the one below:

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

eneThe ENERGY action with label ene calculates the following quantities:
 Quantity   
 Type   
 Description  
ene
scalar
the internal energy: ENERGYCalculate the total potential energy of the simulation box. More details
PRINTPrint quantities to a file. More details ARGthe labels of the values that you would like to print to the file=ene FILEthe name of the file on which to output these quantities=colvar

Notice that this CV is not available with all the MD codes. When it is available, and when replica exchange is also available, metadynamics applied to ENERGY can be used to decrease the number of required replicas.

[!CAUTION] The ENERGY output by PLUMED does not include long tail corrections. Thus when using e.g. LAMMPS "pair_modify tail yes" or GROMACS "DispCorr Ener" (or "DispCorr EnerPres"), the potential energy from ENERGY will be slightly different from the one that is output by the MD code. You should still be able to bias the ENERGY and then reweight your simulation with the correct MD energy values.

[!CAUTION] Acceptance for replica exchange when ENERGY is biased is computed correctly only if all the replicas have the same potential energy function. This is for instance not true when using GROMACS with lambda replica exchange or with plumed-hrex branch.

References

More information about how this action can be used is available in the following articles: - C. Bartels, M. Karplus, Probability Distributions for Complex Systems:  Adaptive Umbrella Sampling of the Potential Energy. The Journal of Physical Chemistry B. 102, 865–880 (1998) - M. Bonomi, M. Parrinello, Enhanced Sampling in the Well-Tempered Ensemble. Physical Review Letters. 104 (2010)

Syntax

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