generate crystal from a given building block

[qzhu2017]

Probably will be useful for mol. xtal which is based on the packing of motifs (e.g., cyclic dimers).

s = pyxtal(molecular=True)
s.from_random(3, 14, ['C1=C(C=C(C=C1[N+](=O)[O-])[N+](=O)[O-])C(=O)O.smi', 'CC1=CC2=C(C=C1)N3CC4=C(C=CC(=C4)C)N(C2)C3.smi'], block='dimer.xyz')

In this case, we will attempt to assemble the packing from the building blocks.

[qzhu2017]

from pyxtal import pyxtal

smiles = ["C1=C(C=C(C=C1[N+](=O)[O-])[N+](=O)[O-])C(=O)O.smi",
          "CC1=CC2=C(C=C1)N3CC4=C(C=CC(=C4)C)N(C2)C3.smi"]

s = pyxtal(molecular=True)
s.from_random(3, 14, smiles, block='xxv')
print(s)

------Crystal from random------
Dimension: 3
Composition: [C1=C(C=C(C=C1[N+](=O)[O-])[N+](=O)[O-])C(=O)O]4[CC1=CC2=C(C=C1)N3CC4=C(C=CC(=C4)C)N(C2)C3]4
Group: P21/c (14)
monoclinic lattice:  25.3254  20.1843  14.2472  90.0000  97.1375  90.0000
Wyckoff sites:
	H4C7N2O6     @ [ 0.3118  0.8145  0.0553]  WP [4e] Site [1] Euler [   0.0    0.0    0.0]
	H18C17N2     @ [ 0.5863  0.7268  0.3577]  WP [4e] Site [1] Euler [   0.0    0.0    0.0]