zagreb_index_m1

skfp.descriptors.zagreb_index_m1(mol: Mol) → int

First Zagreb Index.

Calculates the first Zagreb index [1], defined as the sum of the squares of the degrees of all atoms in the molecule. Also known as simply the Zagreb index. It is a measure of molecular branching.

Parameters:

mol (RDKit Mol object) – The molecule for which the first Zagreb index is to be calculated.

References

[1]

Gutman, Ivan. “Degree-Based Topological Indices” Croatica Chemica Acta 86.4 (2013): 352.

Examples

>>> from rdkit.Chem import MolFromSmiles
>>> from skfp.descriptors import zagreb_index_m1
>>> mol = MolFromSmiles("C1=CC=CC=C1")  # Benzene
>>> zagreb_index_m1(mol)
24