Rst-wham

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RST Utilities

• rst-samples
• rst-wham
• rst-wham-2d

Name

rst-wham

Synopsis

wham [P|Ppi|Pval] hist_min hist_max num_bins tol temperature numpad metadatafile freefile [num_MC_trials randSeed]

Description These programs (wham and wham-2d) implement the Weighted Histogram Analysis Method of Kumar, et al ("Multidimensional free-energy calculations using the weighted histogram analysis method", J. Comput. Chem., 16:1339-1350, 1995). The code generally follows the notation used by Benoit Roux ("The calculation of the potential of mean force using computer simulations", Comput. Phys. Comm., 91:275-282, 1995). Consult these papers for the theoretical background and justification for the method.

Arguments

[P|Ppi|Pval] The first (optional) argument specifies the periodicity of the reaction coordinate. For a nonperiodic reaction coordinate (a distance, for example), it should be left out. "P" means that the reaction coordinate has a periodicity of 360, appropriate for angles. "Ppi" specifies a periodicity of 2*pi, appropriate for angles measured in radians. "Pval" specifies periodicty of some arbitrary amount, val, which should be an integer or floating point number. For example, "P180.0" would be appropriate for an angle with twofold symmetry.

hist_min hist_max Specify the boundaries of the histogram. As a rule, all data points outside the range (hist_min, hist_max) are silently ignored. The only exception is that if an entire trajectory is outside the range, the program halts with an error message. The solution is to remove that file from the metadata file. hist_min and hist_max should be floating point numbers.

num_bins Specifies the number of bins in the histogram, and as a result the number of points in the final PMF. It should be an integer.

Options