Electronic configuration¶

ec attribute is an object from the ElectronicConfiguration class that has additional method for manipulating the configuration. Internally the configuration is represented as a OrderedDict from the collections module where tuples (n, s) (n is the principal quantum number and s is the subshell label) are used as keys and shell occupations are the values

[1]:

from mendeleev import Si

[2]:

Si.ec.conf

[2]:

OrderedDict([((1, 's'), 2),
             ((2, 's'), 2),
             ((2, 'p'), 6),
             ((3, 's'), 2),
             ((3, 'p'), 2)])

the occupation of different subshells can be access supplying a proper key

[3]:

Si.ec.conf[(1, 's')]

[3]:

to calculate the number of electrons per shell type

[4]:

Si.ec.electrons_per_shell()

[4]:

{'K': 2, 'L': 8, 'M': 4}

get the largest value of the pricipal quantum number

[5]:

Si.ec.max_n()

[5]:

Get the largest value of azimutal quantum number for a given value of principal quantum number

[6]:

Si.ec.max_l(n=3)

[6]:

'p'

Find the large noble gas-like core configuration

[7]:

Si.ec.get_largest_core()

[7]:

('Ne', <ElectronicConfiguration(conf="1s2 2s2 2p6")>)

Get the total number of electrons

[8]:

Si.ec.ne()

[8]:

Last subshell

[9]:

Si.ec.last_subshell()

[9]:

((3, 'p'), 2)

Get unpaired electrons

[10]:

Si.ec.unpaired_electrons()

[10]:

Remove electrons by ionizing returns a new configuration with an electron removed

[11]:

ionized = Si.ec.ionize()
print(ionized)

1s2 2s2 2p6 3s2 3p1

We can check that it actually has less electrons:

[12]:

ionized.ne()

[12]:

Spin occupations by subshell

[13]:

Si.ec.spin_occupations()

[13]:

OrderedDict([((1, 's'), {'pairs': 1, 'alpha': 1, 'beta': 1, 'unpaired': 0}),
             ((2, 's'), {'pairs': 1, 'alpha': 1, 'beta': 1, 'unpaired': 0}),
             ((2, 'p'), {'pairs': 3, 'alpha': 3, 'beta': 3, 'unpaired': 0}),
             ((3, 's'), {'pairs': 1, 'alpha': 1, 'beta': 1, 'unpaired': 0}),
             ((3, 'p'), {'pairs': 0, 'alpha': 2, 'beta': 0, 'unpaired': 2})])

Calculate the spin only magnetic moment

[14]:

Si.ec.spin_only_magnetic_moment()

[14]:

2.8284271247461903

Calculate the screening constant using Slater’s rules for 2s orbital

[15]:

Si.ec.slater_screening(n=2, o='s')

[15]:

4.1499999999999995

Standalone use¶

You can use the ElectronicConfiguration as a standalone class and use all of the methods shown above.

[16]:

from mendeleev.econf import ElectronicConfiguration

[17]:

ec = ElectronicConfiguration("1s2 2s2 2p6 3s1")

Get the valence only configuration

[18]:

ec.get_valence()

[18]:

<ElectronicConfiguration(conf="3s1")>