How to use lammps for thousands of small calculations?

Dear Lammps Developers and Users

I have thousands of small simulations from monte carlo simulations using DFT. I want to repeat the do the same calculation with LAMMPS using the same configuration from DFT calculations. I am wondering how to do that with one input file and one data file. I know it can be done with thousands of independent files and read the files one by one using one input file. As reading thousands of files with thousands of time is not efficient, I am wondering do any one know to read all the data file one time for all data and run one by one with one input file?

Thanks very much for your help and I really appreciate it.

Hao

Dear Lammps Developers and Users

I have thousands of small simulations from monte carlo simulations using DFT. I want to repeat the do the same calculation with LAMMPS using the same configuration from DFT calculations. I am wondering how to do that with one input file and one data file. I know it can be done with thousands of independent files and read the files one by one using one input file. As reading thousands of files with thousands of time is not efficient, I am wondering do any one know to read all the data file one time for all data and run one by one with one input file?

your logic doesn’t hold. whether you read a thousand files or just one big file. the effort of parsing is essentially the same, since you have the same amount of numbers that need to be converted from strings into floating point numbers. also the effort of parsing a data file is negligible compared to the effort of running an MD simulation, which is dominated by the computing of the forces.

this all looks to me like you are a subject of the “premature optimization syndrome”.

axel.

Thanks very much, Axel. I have one big file which list thousands of configurations and cell boundaries. Can I use one input file for this problem or need to use a script to split it into thousands of small files? At last, you are totally correct that this is “premature optimization syndrome” as I am planning what to do with the data now.

Hi Axel

Is there a method to read one big file which contains thousands of configurations and do the simulation one by one through lammps?

Thanks very much!

Hao

what LAMMPS can do is listed in the manual. please help yourself.

For sure, but since this is a technique problem, would you like to give some suggestions for this problem? Thanks.

you already outlined a solution yourself in your original post. i pointed out, that the optimization you were looking for is not really an optimization and you agreed. yet you keep making the same request again and again. that is not a technical/technique problem. i have given you the most specific answer i can give you without becoming offensive or attacking you personally. i don’t see a point in spending more time and energy on something that has a perfectly viable and straightforward to implement solution. computers don’t get bored and thus are ideal to use for repetitive tasks. if you need a more creative solution, you will have to figure it out for yourself and the documentation is the point to start. it explains all the commands and all the ways how you can script and interface LAMMPS in whatever way you desire. but if you had started implementing your originally outlined solution, you could already be running your simulations.

Thanks very much for your feedback, Axel. Really appreciate your help. Will follow your suggestions.