Hi Bas,

Thanks for your reply.

I have used the same syntax. But it is showing an Attribute Error: 'tuple object has no attribute 'items'

from __future__ import division
import kwant
import kwant.continuum
import scipy.sparse.linalg
import scipy.linalg
import numpy as np
import sympy
from math import sin, cos, sqrt, pi
import matplotlib.pyplot as plt
hamiltonian = ("""k_x**2 + k_y**2 + k_z**2""")
hamiltonian = kwant.continuum.sympify(hamiltonian)
template = kwant.continuum.discretize_symbolic(hamiltonian)
t = kwant.continuum.build_discretized(template, coords = ('x', 'y', 'z'))
print(t)

AttributeError                            Traceback (most recent call last)
<ipython-input-12-9780451ce368> in <module>
     11 hamiltonian = kwant.continuum.sympify(hamiltonian)
     12 template = kwant.continuum.discretize_symbolic(hamiltonian)
---> 13 t = kwant.continuum.build_discretized(template, coords = ('x','y','z'))
     14 print(t)
     15 hamiltonian

/usr/local/lib/python3.6/dist-packages/kwant/continuum/discretizer.py in build_discretized(tb_hamiltonian, coords, grid_spacing, locals)
    281 
    282     with reraise_warnings():
--> 283         for k, v in tb_hamiltonian.items():
    284             tb_hamiltonian[k] = sympify(v, locals)
    285 

AttributeError: 'tuple' object has no attribute 'items'

What should I do. 

Naveen

On Fri, Mar 29, 2019 at 5:37 PM Bas Nijholt <basnijholt@gmail.com> wrote:

Hi Naveen,

In the documentation you can see that coords require a sequence of strings, so for example:

coords = ('x',)  # for 1D
coords = ('x', 'y', 'z')  # for 3D

Best, Bas

On Fri, Mar 29, 2019 at 12:59 PM Naveen Yadav <naveengunwal72@gmail.com> wrote:

I want to know more about the builid_discretized(tb_hamiltonian, coords).

I did not undersand what should be the syntax to write the coords.Could you please help me by sending an example code for writing coords?

Thanks in Advance.

Naveen
Department of Physics & Astrophysics
University of Delhi
110007

--

With Best Regards
NAVEEN YADAV
Ph.D Research Scholar
Deptt. Of Physics & Astrophysics
University Of Delhi.