Data File Format

Hi all,

I developed a program on Matlab which generates the atom coordinates, bond
and angle information for my problem but I am confused how to make this
output as a file which lammps can understand it as a data file with
read_data command. I tried to copy the output in a text file and save it
with .data format, it worked somehow in one problem but in the other it gave
errors like” unexpected end of data file” for example for the file that
starts like this:

the data format is well described in great detail in the "read_data"
documentation. you have to be careful to make sure it contains all
required sections and columns consistent with your atom_style and
topology and it has empty lines where they are needed.

when you get error messages like the "unexpected end of data file"
one, you are providing an incomplete file. since the data file format
is not self descriptive, it is impossible to say where exactly the
error is. it is definitely impossible to tell you what the problem is
from the little snipped of a file below. i also would advise against
placing potential parameters into the data file. i usually recommend
to write those into a separate file using XXX_coeff commands, so that
one can easily replace forcefield sets via an include file and re-use
the same data file.

i found it sometimes helpful to pass the data file through the
alternate parser that i've written for the topotools plugin in VMD. it
uses a different approach than the reader in LAMMPS and thus would
produce a different error message and the combination of the LAMMPS
and topotools error message is often a good hint at what is amiss.


And you could look at any of the several data files
in the examples dirs to see what one should look like.
The one you pasted into the mail message appears
to have extra new lines between every line. That would
be fatal when the read_data command reads it.