NNQMD Training Dataset
QMD simulations to generate PTO crystal training set for ground- and excited-state NNQMD
QMD Specification: The training datasets consist of 3×3×3 or 4×4×4 unit cells. Each system is thermalized at 300 K using NVT ensemble. A plane-wave basis was used with a cutoff energy of 410 eV for the wave functions and 3,400 eV cutoff for the charge density. Vanderbilt style ultra-soft pseudopotentials (USPPs) were used, and local density approximation (LDA) was used for the exchange-correlation. Only the gamma-point was sampled from the Brillouin zone. Atomic trajectories were obtained using the velocity-Verlet algorithm at time step of 10 a.u. (1.209 fs). In total, 500 frames of QMD trajectory were used. 95% of the total frames were used as training set and 5% frames were so for test. QMD simulations were carried out using the highly parallelized plane-wave based QXMD software.