An excel file containing the numerical data corresponding to all of the DNSs that were run in this study (listed in tables 1 and 2 in the paper). This data set is required to recreate figure 8 in the paper. In total, 17 DNSs were run using the low Péclet equations (Low Pe) and 48 DNSs were run using the standard equations (Standard), as indicated in column A. Columns B-F provide the input parameters whilst columns G-Y provide the external diagnostics. These diagnostics were computed as time averages (AVG) and deviations around these averages (SD) once the system had reached a statistically steady state. We provide the r.m.s. total velocity (u_rms), streamwise velocity (ux_rms), spanwise velocity (uy_rms), vertical velocity (uz_rms), temperature perturbations (T’_rms), vertical length scale (l_z), mixing efficiency (eta), viscous energy dissipation rate (|grad_u|^2), temperature flux (|<wT’>/Pe|) and the Reynolds number based on the Taylor microscale (Re_lambda).