Dear Mauro, > I suppose that the value printed by Quantum Espresso is calculated > using a certain number of MD timesteps. So it should discard the > initial part of the trajectory.
It may be always safe to discard the first part of the trajectories since it started from a particular initial configuration in a quasi equilibrium state. Below is only my thought but may work. You should first calculate the system for a few thousands time steps with temperature regulation (say at 300 K). And you obtain the diffusion coefficient D1 at 300 K evaluated by the QE. Now, hopefully, the system is in an equilibrium state. Next calculate the subsequent MD steps using the option restart_mode = 'restart’, After the calculation, you will obtain a diffusion coefficient D2 calculated by QE. D2 at the equilibrium state is much more reliable than the D1 at the quasi equilibrium state. Repeat the above procedure until you convince can get a converged diffusion coefficient D at 300K. Note that it is also not so difficult to evaluate the diffusion coefficient directory from the trajectories written in the output file. 西館数芽 Kazume NISHIDATE Ph.D Department of Systems Innovation Engineering, Graduate School of Science and Engineering, Iwate University 4-3-5 Ueda, Morioka, Iwate, 020-8551 JAPAN Phone:+81-19-621-6391 kazume.nishid...@gmail.com, nisid...@iwate-u.ac.jp https://sites.google.com/site/nisidatelab/ _______________________________________________ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users