Hello everybody,

I’d like to use the NEB package with a reaxFF potential, but I don’t know which timestep should i use for the minimization required. I’ve checked the manual and I found two contradicting advices:

IMPORTANT NOTE: As explained below, a NEB calculation perfoms a damped dynamics minimization across all the replicas. The mimimizer uses whatever timestep you have defined in your input script, via the timestep command. Often NEB will converge more quickly if you use a timestep about **10x larger than you would normally use for dynamics simulations.**

The damped dynamics minimizers, such as *quickmin* and *fire*), adjust the position and velocity of the atoms via an Euler integration step. Thus you must define an appropriate timestep to use with NEB. **Using the same timestep that would be used for a dynamics run of your system is advised.**

could anyone explain which one should I use?

thanks in advance

Franco Zanotto

Hello everybody,

I'd like to use the NEB package with a reaxFF potential, but I don't know

which timestep should i use for the minimization required. I've checked the

manual and I found two contradicting advices:

IMPORTANT NOTE: As explained below, a NEB calculation perfoms a damped

dynamics minimization across all the replicas. The mimimizer uses whatever

timestep you have defined in your input script, via the timestep command.

Often NEB will converge more quickly if you use a timestep about 10x larger

than you would normally use for dynamics simulations.

The damped dynamics minimizers, such as quickmin and fire), adjust the

position and velocity of the atoms via an Euler integration step. Thus you

must define an appropriate timestep to use with NEB. Using the same timestep

that would be used for a dynamics run of your system is advised.

could anyone explain which one should I use?

how about starting with the shorter timestep and checking to see, if

you get faster convergence by increasing it?

axel.