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Short helpfile for action VES_DELTA_F
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The following arguments are compulsory: 

                 FILE_F - names of files containing local free energies and 
                          derivatives. The first one, FILE_F0, is used as reference for all the 
                          free energy differences. You can use multiple instances of this 
                          keyword i.e. FILE_F1, FILE_F2, FILE_F3... 
             BIASFACTOR - ( default=0 ) the \f$\gamma\f$ bias factor used for 
                          well-tempered target \f$p(\mathbfs)\f$. 
                 M_STEP - ( default=1.0 
              AV_STRIDE - ( default=500 ) number of simulation steps between alpha 
                          updates 
             ALPHA_FILE - ( default=ALPHA ) file name for output minimization 
                          parameters 

In addition you may use the following options: 

  NUMERICAL_DERIVATIVES - ( default=off ) calculate the derivatives for these 
                          quantities numerically 
              NORMALIZE - ( default=off ) normalize all local free energies so that 
                          alpha will be (approx) \f$\Delta F\f$ 
           NO_MINTOZERO - ( default=off ) leave local free energies as provided, 
                          without shifting them to zero min 
            DAMPING_OFF - ( default=off ) do not use an AdaGrad-like term to rescale 
                          M_STEP 
                 SERIAL - ( default=off ) perform the calculation in serial even if 
                          multiple tasks are available 
       MULTIPLE_WALKERS - ( default=off ) use multiple walkers connected via MPI for 
                          the optimization 
                    ARG - the input for this action is the scalar output from one or 
                          more other actions. The particular scalars that you will use are 
                          referenced using the label of the action. If the label appears on its 
                          own then it is assumed that the Action calculates a single 
                          scalar value. The value of this scalar is thus used as the input 
                          to this new action. If * or *.* appears the scalars calculated 
                          by all the proceeding actions in the input file are taken. 
                          Some actions have multi-component outputs and each component of 
                          the output has a specific label. For example a \ref DISTANCE 
                          action labelled dist may have three components x, y and z. To take 
                          just the x component you should use dist.x, if you wish to take 
                          all three components then use dist.*.More information on the 
                          referencing of Actions can be found in the section of the manual on the 
                          PLUMED \ref Syntax. Scalar values can also be referenced using 
                          POSIX regular expressions as detailed in the section on \ref 
                          Regex. To use this feature you you must compile PLUMED with the 
                          appropriate flag. You can use multiple instances of this keyword i.e. 
                          ARG1, ARG2, ARG3... 
                   TEMP - temperature is compulsory, but it can be sometimes fetched 
                          from the MD engine 
              TG_STRIDE - ( default=1 ) number of AV_STRIDE between updates of target 
                          \f$p(\mathbfs)\f$ and reweighing factor \f$c(t)\f$ 
               TAU_MEAN - exponentially decaying average for alpha (rescaled using 
                          AV_STRIDE). Should be used only in very specific cases 
          INITIAL_ALPHA - ( default=0 ) an initial guess for the bias potential 
                          parameter alpha 
           PRINT_STRIDE - ( default=10 ) stride for printing to ALPHA_FILE 
                    FMT - specify format for ALPHA_FILE 
                RESTART - allows per-action setting of restart (YES/NO/AUTO) 


