Dear all, I tried to perform md simulations in Quantum Espresso in 2 different ways: 1) simply run a single continuous trajectory (e.g. 10 steps) 2) run first step of MD as a new calculation (restart_mode = from_scratch, default) and run all other (remaining 9) steps as restarts (restart_mode = restart), doing this for every step
As a result after a few steps the total energies, atomic forces and position started to deviate between two approaches. I suspect that some information from the previous step may be dropped during the restart (e.g. by using the first-order Euler scheme instead of the Verlet algorithm), eventually leading to such divergence. So my question is: what is restart algorithm for MD in quantum espresso and is there any possibility to use method 2 (see above) without accumulation of the integration errors? Also can someone clarify why if i specify nstep = 1 in my input file (request to perform a single MD step), the program actually makes 2 MD steps? Thank you, Alexey -- Dr. Alexey V. Akimov Postdoctoral Research Associate Department of Chemistry University of Rochester aakimov at z.rochester.edu
