Input and relevant data files for "The Physics of Changing Tectonic Regimes: Implications for the Temporal Evolution of Mantle Convection and the Thermal History of Venus." Each data set was used to generate figures in text, and was used with, or obtained from, CitcomS (v3.3). diagnostic.dat contains internal metrics [#step time Mobility Tint T_asthen_avg D U Uc RMS_Velocity] Where #step is iteration number, time is the non dimensional diffusion time scale for the step, Mobility is defined in text, Tint is the mid mantle temperature (average), T_asthen_avg is the upper mantle temperature (average), D U Uc not used, and RMS_Velocity is the root mean square velocity. Nusselt.dat contains heat flow information [time, surface nusselt number, basal nusselt number]. Time is the non dimensional diffusion time scale for the step. nusselt numbers are nondimesional heatflow from the surface (lithosphere) and base (core). Melt2.dat contains melting information. #step is iteration number, time is the non dimensional diffusion time scale for the step, non-dimensional melt the input.* file is the model input file used with CitcomS (v3.3) that includes all parameters used for the reference case. Variations from this file are described in text.