#!/usr/bin/env python
from sys import argv
import ase.io
from tsase.io.lammps import read_lammps, write_lammps

###add usage help

poscar = True
if argv[1].startswith('POSCAR') or argv[1].startswith('CONTCAR'):
    atoms = ase.io.read(argv[1])  
else:
    atoms = read_lammps(argv[1])
    poscar = False

if len(argv) == 3:
    outname=argv[2]
else:
    if poscar:
        outname='lmps_pos'
    else:
        outname='POSCAR'

if poscar:
    write_lammps(outname, atoms)
else:
    ase.io.write(outname, atoms)


