Chimie Théorique » QMX

from ase import Atoms, Atom, view

from gpaw import GPAW

logo = """\

 H   HH HHH

H H H   H

HHH  H  HH

H H   H H

H H HH  HHH"""

d = 0.8

atoms = Atoms()

for y, line in enumerate(logo.split('\n')):

    for x, c in enumerate(line):

        if c == 'H':

            atoms.append(Atom('H', [d * x, -d * y, 0]))

atoms.center(vacuum=2.0)

view(atoms)

if 0:

    calc = GPAW(nbands=30)

    atoms.set_calculator(calc)

    atoms.get_potential_energy()

    calc.write('ase-logo.gpw')

else:

    calc = GPAW('ase-logo.gpw', txt=None)

density = calc.get_pseudo_density()

image = density[..., density.shape[2] // 2]

if 1: # scale colors to wiki background / foreground

    import numpy as np

    background = np.array([[[19., 63., 82.]]]).T / 255 # 1c4e63 blueish

    foreground = np.array([[[1., 1., 1.]]]).T  # white

    image = background + image / image.max() * (foreground - background)

    image = image.T

else: # Use a standard color scheme

    image = pl.cm.hot(image.T)

import pylab as pl

x, y, z = atoms.cell.diagonal()

pl.figure(1, figsize=(8, 8 * y / x), dpi=80)

pl.axes([0, 0, 1, 1])

pl.imshow(image,

          origin='lower',

          extent=[0, x, 0, y],

          aspect='equal',

          interpolation='spline16')

pl.axis('off')

pl.savefig('ase-logo.png', dpi=80)

pl.show()