According to our experience in the development of PES, we firstly conducted an exhaustive examination of various NN parameters. With a comprehensive test, the NN's optimal architecture was identified. The architecture of the PIP-NN encompasses 1826 PIP terms as the input, with 10 neurons in each hidden layer, and a single potential energy output, resulting in 18,391 non-linear fitting parameters. methyl shift with all other coordinates fixed at the CH3NC equilibrium. Again, the potential on the PIP-NN PES is in excellent agreement with the ab initio results.