#!/usr/bin/env python
# coding: utf-8

# # 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

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from mendeleev import Si


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Si.ec.conf


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

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


# to calculate the number of electrons per shell type

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Si.ec.electrons_per_shell()


# get the largest value of the pricipal quantum number

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Si.ec.max_n()


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

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Si.ec.max_l(n=3)


# Find the large noble gas-like core configuration

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Si.ec.get_largest_core()


# Get the total number of electrons

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Si.ec.ne()


# Last subshell

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Si.ec.last_subshell()


# Get unpaired electrons

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Si.ec.unpaired_electrons()


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

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


# We can check that it actually has less electrons: 

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ionized.ne()


# Spin occupations by subshell

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Si.ec.spin_occupations()


# Calculate the spin only magnetic moment

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Si.ec.spin_only_magnetic_moment()


# Calculate the screening constant using Slater's rules for `2s` orbital

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


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

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from mendeleev.econf import ElectronicConfiguration


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


# Get the valence only configuration

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ec.get_valence()