Creating a dataset for subsequent fitting is a critical aspect of the goal to obtain a robust and precise PES. Many approaches are based on direct-dynamics, where configurations, energies and forces are obtained at a variety of temperatures (using NVT simulations) or total energies (using NVE simulations) via direct calls to software that generates these data. Our work using this approach dates back to 2003, where we used NVE direct(MP2)-dynamics to generate a dataset that was fit using PIPs for CH + 5 . More recently, "MD17" datasets have been developed using NVT direct-dynamics at 500 K 29 for a number of molecules. These datasets have been used extensively by the ML community to test methods. A recent critique of this dataset noted the limited range of the configurations and energies obtained from this sampling and another more recent one noted the limitation to non-reactive potentials. In the current application, we continue to employ direct dynamics, but given the size of the molecule and the need for long-time dynamics, DFT is not feasible. Instead, we use the well-known MM3 force field 60 in NVT molecular dynamics at 100 K, 500 K, 1000 K, and 2500 K, using the Tinker package. Specifically, the "dynamic" program was used to calculate trajectories using the efficient and realistic MM3 force field with an equilibration time of 100 ps followed by 1 ns (T = 500 K and T = 1000 K) or 2 ns (T = 2500 K) of simulation with a time step of 1 fs and a constant temperature Nosé-Hoover thermostat.