For a given research target, the sampled data should be representative enough with wide ranges, and as small as possible for efficiency. If the sampled configuration space is not enough, the prediction for regions lacking points is in principle not reliable. Data sampling is relevant to data quality. The DFT and the CCSD(T) PESs are different, and may require different samplings to represent them, although low-level direct dynamics or PESs can be used for preliminary sampling.