Is the systematic algorithm reproducible?
Yes, if you start from the same conformation. In simple molecules the systematic algorithm is almost always inclusive of all (important) minima. As molecules become more complicated the default grid size, while likely correct in finding all classes of minima, may skip some minima. For example, the single “gauche plus-gauche minus” [-120,+120] conformation of olefins might bifurcate into multiple minima as steric bulk increases. It is likely that one of the two new minima would be found using the standard systematic approach. But ‘which one’ would depend on the initial conformation. To ensure you find all minima, it is useful to increase the default rotor values. Doing so will increase computational time; an alternate approach would be to switch over to the Monte-Carlo algorithm. Another example of the initial conformer affecting systenatuc results can be found by inspecting an 8 member carbon chain: “C1-C2-C3-C4-C5-C6-C7-C8”. For illustrative purposes consider the central “C4-C5” bond
