PressureFromTestVolume
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class PressureFromTestVolume : public feasst::Modify
Compute pressure using test volume changes. See https://doi.org/10.1063/1.472721
Hard systems must consider only volume reductions (i.e., negative delta_volume).
\(p = \frac{1}{\beta \Delta V}\ln \left\langle \left(\frac{V'}{V}\right)^N e^{-\beta\Delta U}\right\rangle \)
The output block standard deviation used the error propagation formula:
\( f = \ln(g) \)
\( \sigma_f = \sigma_g/|g| \)
where \(\sigma_g\) is a block average from the term above in the ensemble average.
Arguments
delta_volume: test volume change (default: 1e-4).