# Some common sense question

Thanks for Alex’s kind help.
I’m sorry about the bad description for my question. Actually I want to calculate the thermal conductivity, I adopt the Green-Kubo method, by this method the total energy should keep in a small fluctuation. But for my simulation, I ran the simulation for 10 million steps and the total energy increased about 0.2%. Also I ran the example for calculating thermal conductivity , after I ran 10million steps, the total energy of example also increased about 0.2%, is that normal? If the energy increased a little, is the result reliable? Or can I only count the smooth part of total energy (the total energy is in a fluctuation range) and do the thermal conductivity calculation? For example , if I want to calculate the average of temperature between line 50 to 200, how can I do in Lammps? I can use the matlab to do it, but I don’t how to do in the lammps input. Sorry for these stupid questions, I have bothered by these question for a week, but I can’t found any answer online. It is highly appreciate if anyone can recommend any reference information to me.

Thanks for Alex's kind help.
I'm sorry about the bad description for my question. Actually I want to
calculate the thermal conductivity, I adopt the Green-Kubo method, by this
method the total energy should keep in a small fluctuation. But for my
simulation, I ran the simulation for 10 million steps and the total energy
increased about 0.2%. Also I ran the example for calculating thermal
conductivity , after I ran 10million steps, the total energy of example
also increased about 0.2%, is that normal? If the energy increased a
little, is the result reliable? Or can I only count the smooth part of
total energy (the total energy is in a fluctuation range) and do the
thermal conductivity calculation? For example , if I want to calculate the
average of temperature between line 50 to 200, how can I do in Lammps? I
can use the matlab to do it, but I don't how to do in the lammps input.
Sorry for these stupid questions, I have bothered by these question for a
week, but I can't found any answer online. It is highly appreciate if
anyone can recommend any reference information to me.

​nobody can answer these questions in such generality without knowing the
details of your simulations, as mentioned before, this is something to be