Getting the atom coordinates in a bulk system

ASE
1

Hello,

I just started learning how to use ASE. I’m wondering can I get every atoms coordinates after a bulk system is generated? say I have
from ase.spacegroup import crystal

a = 5.64
nacl = crystal([‘Na’, ‘Cl’], [(0, 0, 0), (0.5, 0.5, 0.5)], spacegroup=225,
cellpar=[a, a, a, 90, 90, 90])

What command should use to get Na Cl coordinates.
Any help would be greatly appreciated!

2

nacl will be an Atoms object, so be sure to look up the documentation for the Atoms object.

A good starting point is to click on “Modules” on wiki.fysik.dtu.dk/ase, and then find it in the list.

To also answer the question, nacl.get_positions() returns the positions as an array.

3

Thank you so much for quick reply. It helps a lot!

4

Hello,

May I ask another question?
I was trying to read vasp input as the following way

from ase.io import vasp
vasp.read_vasp(filename=‘CONTCAR’)

And it reports an error says
iofunc() missing 1 required positional argument: ‘file’

I’m not sure what it means and I’ve checked the working directory and file name are correct.
Any help would be greatly appreciated!

5

Hi Qi,
file is a positional argument, so the syntax would look like this:

atoms = vasp.read_vasp('CONTCAR')

Or, generally:

from ase.io import read
atoms = read('CONTCAR')