Quick Build function

[qzhu2017]

A list of prototypes for quick build

Name: 'diamond'
Spg: 227,
Element: ['C']
wp: [['8a']]
l: 3.56

Name: 'zincblende'
Spg: 216,
Element: ['Zn', 'S']
wp: [[], []]
l: 5.41

Name: 'rocksalt'
Spg:
Element: ['Zn', 'S']
wp:
l:

Name: 'wurzite'
Name: 'graphite'
Name: 'alpha quartz'
Name: 'beta quartz'
Name: 'alpha cristobalite'
Name: 'beta cristobalite'

[qzhu2017]

as well as topology strings

[qzhu2017]

Major Feature enhancement for v0.6.0

[qzhu2017]

>>> from pyxtal import pyxtal
>>> c = pyxtal()
>>> c.from_prototype('graphite')
>>> c

------Crystal from Build------
Dimension: 3
Composition: C4
Group: P 63/m m c (194)
  2.4600,   2.4600,   6.7000,  90.0000,  90.0000, 120.0000, hexagonal
Wyckoff sites:
	 C @ [ 0.3333  0.6667  0.2500], WP [2c] Site [-622m2]
	 C @ [ 0.0000  0.0000  0.2500], WP [2b] Site [-622m2]