.. highlight:: yaml

.. _sec-yaml-elements:

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Elements
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``element`` entries are needed only when defining custom elements that are not
standard chemical elements, or defining specific isotopes.

The fields of an ``element`` entry are:

``symbol``
    The symbol used for the element, as used when specifying the composition of
    species.

``atomic-weight``
    The atomic weight of the element, in unified atomic mass units (dalton).

``atomic-number``
    The atomic number of the element. Optional.

``entropy298``
    The standard molar entropy of the element at 298.15 K. Optional.