Reaxff lammps

The periodic system was composed of 5 molecules each of methane, propene, o -xylene, and benzene plus 200 molecules of oxygen. The system was minimized using low-temperature MD and then equilibrated at 2500 K using a temperature damping constant of 0.1 ps and a MD time step of 0.1 fs. Starting with the equilibrated configuration, an NVT−MD simulation was performed at 2500 K using a temperature damping constant of 0.5 ps and a MD time step of 0.1 fs with a total simulation time of 500 ps,
Question about how to write the input command in input file as above mention sequence. thanks

These are all standard steps in setting up an MD simulation and the details can be looked up in the LAMMPS manual. What the LAMMPS manual (and this forum) cannot teach you, however, is learning how to do MD simulations in general. There are tutorials for that, there are text books, there are advisers/tutors that can show and explain to you.

Thanks for reply,
But I view the manual, I have some problem about input file
timestep 0.1
fix min all nve
fix temp all temp/berendsen 300.0 2500.0 100.0
run 1000000
unfix temp
reset_timestep 0
unfix min
timestep 0.1
fix 2 all nvt temp 300.0 2500.0 500.0
run 5000000
but not provide the accurate result as published in the paper " Application of the ReaxFF Reactive Force Field to Reactive Dynamics of Hydrocarbon Chemisorption and Decomposition". I am little confused. thanks

That input does not do what the quoted description says. For example, you have two temperature ramps, but no low temperature equilibration, no high temperature equilbration, and no production run at fixed temperature. LAMMPS is a computer program and will do exactly what you tell it to do, but you need to know and understand what to ask it. The LAMMPS manual is like a owner’s manual of a car: it will tell you where all the knobs and levers are, but it cannot teach you how to drive.

As I already wrote, discussing how to do MD properly is not a LAMMPS forum topic.