  Molecular dynamics is often considered as a numerical experiment. The error
bars on the results are therefore mandatory, but sometimes difficult to
determine and computationally demanding. As a low-cost approach, we describe
the application of the bootstrap (BS) method to the quantification of
uncertainties pertaining to the time correlation functions. We chose the
autocorrelation functions of velocity and interdiffusion current for a binary
ionic mixture as a test bed, and we assessed the merit of the Darken
approximation relating both of them. The intrinsic errors related to phase
space sampling is investigated comparing the BS method with the reference
method of replica. We also study how the BS method can assist in addressing the
finite size effects.
