  Extended Lagrangian Born-Oppenheimer molecular dynamics (XL-BOMD) in its most
recent shadow potential energy version has been implemented in the
semiempirical PyTorch-based software PySeQM. The implementation includes finite
electronic temperatures, canonical density matrix perturbation theory, and an
adaptive Krylov Subspace Approximation for the integration of the electronic
equations of motion within the XL-BOMB approach (KSA-XL-BOMD). The PyTorch
implementation leverages the use of GPU and machine learning hardware
accelerators for the simulations. The new XL-BOMD formulation allows studying
more challenging chemical systems with charge instabilities and low electronic
energy gaps. Current public release of PySeQM continues our development of
modular architecture for large-scale simulations employing semiempirical
quantum mechanical treatment. Applied to molecular dynamics simulation of 840
carbon atoms, one integration time step executes in 4 seconds on a single
Nvidia RTX A6000 GPU.
