From: Giacomo Fiorin (
Date: Thu Sep 14 2017 - 09:05:38 CDT

Most likely TopoTools has detected the type identifiers from the atom
names, which is what is available in a PDB.

A LAMMPS data file also contains information about type identifiers (which
are numbers in LAMMPS, strings in many other programs) and connectivity.
The PDB file contains neither, and it is your responsibility to assign
these fields according to the force field you are using.


On Thu, Sep 14, 2017 at 9:07 AM, Rajesh <> wrote:

> I am converting a .pdb file to lammpsdata using topotools. The file has
> only two types of atoms carbon and hydrogen But in converted file it shows
> 176 types of atoms. How can I change this to actual number of atoms.
> Thanks
> Rajesh

Giacomo Fiorin
Associate Professor of Research, Temple University, Philadelphia, PA
Contractor, National Institutes of Health, Bethesda, MD