Action: VES_DELTA_F
| Module | ves |
|---|---|
| Description | Usage |
| Implementation of VES Delta F method |   |
Output components
This action calculates the values in the following table. These values can be referenced elsewhere in the input by using this Action's label followed by a dot and the name of the value required from the list below.
| Name | Type | Description |
|---|---|---|
| bias | scalar | the instantaneous value of the bias potential |
| rct | scalar | the reweighting factor c(t) |
| work | scalar | the work done by the bias in one AV_STRIDE |
Input
The arguments that serve as the input for this action are specified using one or more of the keywords in the following table.
| Keyword | Type | Description |
|---|---|---|
| ARG | scalar | the labels of the scalars on which the bias will act |
Further details and examples
Text from manual goes here
Syntax
The following table describes the keywords and options that can be used with this action
| Keyword | Type | Default | Description |
|---|---|---|---|
| ARG | input | none | the labels of the scalars on which the bias will act |
| FILE_F | compulsory | none | names of files containing local free energies and derivatives |
| BIASFACTOR | compulsory | 0 | the gamma bias factor used for well-tempered target p(s) |
| M_STEP | compulsory | 1.0 | the mu step used for the Omega functional minimization |
| AV_STRIDE | compulsory | 500 | number of simulation steps between alpha updates |
| ALPHA_FILE | compulsory | ALPHA | file name for output minimization parameters |
| NUMERICAL_DERIVATIVES | optional | false | calculate the derivatives for these quantities numerically |
| TEMP | optional | not used | temperature is compulsory, but it can be sometimes fetched from the MD engine |
| NORMALIZE | optional | false | normalize all local free energies so that alpha will be (approx) Delta F |
| NO_MINTOZERO | optional | false | leave local free energies as provided, without shifting them to zero min |
| TG_STRIDE | optional | not used | number of AV_STRIDE between updates of target p(s) and reweighing factor c(t) |
| TAU_MEAN | optional | not used | exponentially decaying average for alpha (rescaled using AV_STRIDE) |
| INITIAL_ALPHA | optional | not used | an initial guess for the bias potential parameter alpha |
| DAMPING_OFF | optional | false | do not use an AdaGrad-like term to rescale M_STEP |
| PRINT_STRIDE | optional | not used | stride for printing to ALPHA_FILE |
| FMT | optional | not used | specify format for ALPHA_FILE |
| SERIAL | optional | false | perform the calculation in serial even if multiple tasks are available |
| MULTIPLE_WALKERS | optional | false | use multiple walkers connected via MPI for the optimization |
| RESTART | optional | not used | allows per-action setting of restart (YES/NO/AUTO) |