2.4 Remarks on the selection of potential functions

Empirical and semi-empirical potentials could make very fast calculations. However, the artificial potential due to the analytic functional form could sometimes lead to a completely different energy landscape (especially when it comes to high pressure). Hence it is always better to do simulation at DFT level if possible. Meanwhile, we are aware that there are some attempts to make the high quality potentials by aritificial neural networks 59, which is based on pure fitting of electronic structure data employing very flexible functions. Although it seems very promising, the fitting proceedure is still time-consuming and needs further improvement.