pyelementary

Yet another elements package

Elementary is another elements package defined in Python. It is written to be usable with a number of different unit systems and classes. At its most minimal, it has no dependencies outside the main Python library. However, the real point of the package is to automagically work with a number of units classes and be generally flexible.

Usage

Standard

You can use Elementary immediately by importing the standard Element class. Please see the documentation for more. Each element is defined uniquely to allow for is comparisons.

In [1]: import pyelementary as elm

In [2]: h = elm.Element(atomic_number=1)

In [3]: h is elm.Element(name="hydrogen")
Out[3]: True

In [4]: h.mass
Out[4]: 1.00782503223

Supported attributes include:

• atomic_number
• symbol
• name
• mass (in atomic mass units)
• period
• group
• covalent_radius (in angstrom)

Each attribute can be used to obtain an Element or list of Elements. Floats are rounded to the nearest 4 decimals when using Element().

In [5]: elm.Element(mass=1.0078)
Out[5]: Element(name='hydrogen', symbol='H', atomic_number=1, mass=1.00782503223, period=1, group=1, covalent_radius=0.31)

Using Element() to retrieve an element can be quite slow, as a number of different cases are checked. If your search is more defined, you can access registries for each attribute directly at Element.registry. Keys for all floats are rounded to 4 decimal places.

In [6]: elm.Element.registry.mass[1.0078]
Out[6]: Element(name='hydrogen', symbol='H', atomic_number=1, mass=1.00782503223, period=1, group=1, covalent_radius=0.31)

For attributes where multiple elements have the same value, a sorted tuple of elements is returned.

In [8]: elm.Element(period=5)
Out[8]:
(Element(name='rubidium', symbol='Rb', atomic_number=37, mass=84.9117897379, period=5, group=1, covalent_radius=2.2),
 Element(name='strontium', symbol='Sr', atomic_number=38, mass=87.9056125, period=5, group=2, covalent_radius=1.95),
 Element(name='yttrium', symbol='Y', atomic_number=39, mass=88.9058403, period=5, group=3, covalent_radius=1.9),
 Element(name='zirconium', symbol='Zr', atomic_number=40, mass=89.9046977, period=5, group=4, covalent_radius=1.75),
 Element(name='niobium', symbol='Nb', atomic_number=41, mass=92.906373, period=5, group=5, covalent_radius=1.64),
 Element(name='molybdenum', symbol='Mo', atomic_number=42, mass=97.90540482, period=5, group=6, covalent_radius=1.54),
 Element(name='technetium', symbol='Tc', atomic_number=43, mass=97.9072124, period=5, group=7, covalent_radius=1.47),
 Element(name='ruthenium', symbol='Ru', atomic_number=44, mass=101.9043441, period=5, group=8, covalent_radius=1.46),
 Element(name='rhodium', symbol='Rh', atomic_number=45, mass=102.905498, period=5, group=9, covalent_radius=1.42),
 Element(name='palladium', symbol='Pd', atomic_number=46, mass=105.9034804, period=5, group=10, covalent_radius=1.39),
 Element(name='silver', symbol='Ag', atomic_number=47, mass=106.9050916, period=5, group=11, covalent_radius=1.45),
 Element(name='cadmium', symbol='Cd', atomic_number=48, mass=113.90336509, period=5, group=12, covalent_radius=1.44),
 Element(name='indium', symbol='In', atomic_number=49, mass=114.903878776, period=5, group=13, covalent_radius=1.42),
 Element(name='tin', symbol='Sn', atomic_number=50, mass=119.90220163, period=5, group=14, covalent_radius=1.39),
 Element(name='antimony', symbol='Sb', atomic_number=51, mass=120.903812, period=5, group=15, covalent_radius=1.39),
 Element(name='tellurium', symbol='Te', atomic_number=52, mass=129.906222748, period=5, group=16, covalent_radius=1.38),
 Element(name='iodine', symbol='I', atomic_number=53, mass=126.9044719, period=5, group=17, covalent_radius=1.39),
 Element(name='xenon', symbol='Xe', atomic_number=54, mass=131.9041550856, period=5, group=18, covalent_radius=1.4))

These can be narrowed down with multiple keyword arguments.

In [9]: elm.Element(period=5, group=17)
Out[9]: (Element(name='iodine', symbol='I', atomic_number=53, mass=126.9044719, period=5, group=17, covalent_radius=1.39),)

Units

The default units in the standard elements library are:

• mass: atomic mass units
• length: angstrom

Sources

The data in the standard package are sourced, with much gratitude, from qcelemental version 0.23.0. Please see the documentation for qcelemental for full details. The covalent radii are obtained from Alvarez 2008.

Copyright

Copyright (c) 2022, Lily Wang

Acknowledgements

Project based on the Computational Molecular Science Python Cookiecutter version 1.6.