[QE-users] Best way to choose dt and nstep in AIMD/CPMD simulation using cp.x code in quantum espresso

[Jayraj Anadani]

*Hello QE Community,*
According to the user guide of cp.x we can use a larger time step "dt" for
electron dynamics = "cg" but for my system of 54 atoms (metallic) at 2000 K
temperature, it takes a lot of time to take 500 steps for 36 core, 72
nodes.
*input file description :*
-54 binary atoms 50% each
-dt = 40, nstep = 500 (for cp.x code 1 a.u.=2.4189 * 10^-17 s ) ~ 0.5 ps
-ion_temp = 2000 K , nose frequency (fnosep) = 40 THz , number of
thermostats in the Nose-Hoover chain( nhpcl ) = 4
*Questions*:
1) is there any way to balancing between timestep "dt" and number of CP-MD
steps "nstep"  to achieve fast simulation ?,
2) In comparison with VASP most of the simulation like NVT, NPT, NVE took 3
to 5 ps to equilibrate at a certain temperature so is there any strategy to
speed up the calculation ?

thank you
regards

jayraj anadani
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20220915/308a38fb/attachment.html>