Ovito data file visualization

I loaded a data file and I get below error;
Atoms section must precede Velocities section in data file (error in line 160051).

I checked that atom data are above velocities.
Let me know if anyone knows how to overcome this.


I think you are the first one facing this kind of problem. Can you say some more about the origin of the data file? Which code/tool was used to write the file?

If you like, we can analyze your file in more detail to find out why OVITO refuses to read it. Please post the file here or send a download link to [email protected].


Hi ,

I sent the data file to [[email protected]].
Let me know if you can see the issue

Thanks for sending the file.

The Pair Coeffs section in your data file consists of only two lines but the file header says it has 14 atom types:

Pair Coeffs # lj/cut/gpu

1 1 1
2 5 1

The Pair Coeffs section is supposed to contain one line per atom type. This is the reason why OVITO’s file reader gets confused and misses the beginning of the Atoms section.


Hi I emailed the file,I get the same issue even though pair coeffs are correct.Please advice

I was able to open the file you sent yesterday in OVITO 3.10.4 and 3.10.6. So this

Atoms section must precede Velocities section in data file (error in line 160051).

error seems to be fixed in the new file.

However, it seems like your data files contains reduced atomic coordinates. Please note, that the data file reader in OVITO expects Cartesian coordinates. If you want to use reduced coordinates you can use the lammps dump format instead. This features automatic conversion from reduced to Cartesian coordinates.