question about lammps

thank you for the prompt reply.

about excel file : I mean, in many sources ''read_data" commend is used for creating geometry of simulation and this data file is mostly an excel file with number of atoms and their Cartesian coordinates (x-y-z). I asked ,how can I create this data file ? I know this file is created by another programming language like C or excel , but I don’t know how can I do this work ? what kind of initial information I need?

thank you for your consideration.

thank you for the prompt reply.

about excel file : I mean, in many sources ''read_data" commend is used for
creating geometry of simulation and this data file is mostly an excel file
with number of atoms and their Cartesian coordinates (x-y-z). I asked ,how
can I create this data file ? I know this file is created by another
programming language like C or excel , but I don't know how can I do this
work ? what kind of initial information I need?

i don't know of anybody that has tried to generate a data file in
excel. this seems like an odd choice to me.
more common are C/C++, fortran, python, perl or tcl.

the documentation for the read_data command describes the structure
and contents of a data file in great detail (i.e. you'll have to spend
some time reading and probable some more time re-reading it).

there are also several tools that can write data files based on other
inputs. since the file format is extremely flexible, some user input
is needed and generic solutions are not possible.
some external tools and frontends are listed here:
http://lammps.sandia.gov/prepost.html
if you are a python programmer, you might want to look at Pizza.py as
well: http://pizza.sandia.gov/

axel.