One key conceptual difference between the computational and experimental domains concerns the objects under study, i.e. the "samples". In the computational domain, a sample is an immutable concept: a set of atomic coordinates forming an input of an electronic structure calculation, or a set of boundary conditions for a combustion problem. The outcome of the calculation is usually a property of the original sample (e.g. the energy of that structure, or the adiabatic flame temperature for that mixture and state); sometimes, a new sample may be generated by the calculation (e.g. a relaxed geometry, or an outlet mixture composition and its state). Each of these samples can be easily and separately represented by a digital twin, and each of those samples can be reused in further computations, if necessary.