Chemical symbols

class ase.symbols.Symbols(numbers)[source]

A sequence of chemical symbols.

atoms.symbols is a ase.symbols.Symbols object. This object works like an editable view of atoms.numbers, except its elements are manipulated as strings.

Examples:

>>> from ase.build import molecule
>>> atoms = molecule('CH3CH2OH')
>>> atoms.symbols
Symbols('C2OH6')
>>> atoms.symbols[:3]
Symbols('C2O')
>>> atoms.symbols == 'H'
array([False, False, False,  True,  True,  True,  True,  True,  True], dtype=bool)
>>> atoms.symbols[-3:] = 'Pu'
>>> atoms.symbols
Symbols('C2OH3Pu3')
>>> atoms.symbols[3:6] = 'Mo2U'
>>> atoms.symbols
Symbols('C2OMo2UPu3')
>>> atoms.symbols.formula
Formula('CCOMoMoUPuPuPu')

The ase.formula.Formula object is useful for extended formatting options and analysis.