partition_chem_env¶
-
Cartesian.
partition_chem_env
(follow_bonds=4)[source]¶ - This function partitions the molecule into subsets of the
- same chemical environment.
- A chemical environment is specified by the number of
- surrounding atoms of a certain kind around an atom with a certain atomic number represented by a tuple of a string and a frozenset of tuples.
- The
follow_bonds
option determines how many branches the - algorithm follows to determine the chemical environment.
Example: A carbon atom in ethane has bonds with three hydrogen (atomic
number 1) and one carbon atom (atomic number 6).- If
follow_bonds=1
these are the only atoms we are interested in and the chemical environment is:
('C', frozenset([('H', 3), ('C', 1)]))
- If
follow_bonds=2
we follow every atom in the chemical - enviromment of
follow_bonds=1
to their direct neighbours.
In the case of ethane this gives:
('C', frozenset([('H', 6), ('C', 1)]))
In the special case of ethane this is the whole molecule; in other cases you can apply this operation recursively and
stop afterfollow_bonds
or after reaching the end of branches.Parameters: follow_bonds (int) – Returns: The output will look like this: { (element_symbol, frozenset([tuples])) : set([indices]) } A dictionary mapping from a chemical environment to the set of indices of atoms in this environment.
Return type: dict