CML element formula

Abstract	false (This can be used in an instance)
Nillable	false (Instance values cannot use xsi:nil)
Target Namespace	http://www.xml-cml.org/schema/cml2/core
Declared Namespaces	xmlns:val=http://www.w3.org/1999/XSL/TransformX xmlns:stm=http://www.xml-cml.org/schema/stmml xmlns:xsd=http://www.w3.org/2001/XMLSchema xmlns:xlink=http://www.w3.org/1999/xlink xmlns:cml=http://www.xml-cml.org/schema/cml2/core xmlns=http://www.xml-cml.org/schema/cml2/core

<xsd:element name="formula" id="el.formula">
    <xsd:annotation>
        <xsd:documentation>
            <div class="summary">The stochiometry of the molecule.</div>
            <div class="description">
                <p>
It is
defined by
                    <tt>atomArray</tt>
s each with a list of elementTypes and their
counts (or default=1). All other information in the
                    <tt>atomArray</tt>
is ignored.
                    <tt>formula</tt>
are nestable so that aggregates (e.g. hydrates,
salts, etc.) can be described. CML does not require that formula information
is consistent with (say) crystallographic information; this allows for
experimental variance.
                </p>
                <p>An alternative briefer representation is also available through the
                    <tt>conciseForm</tt>
. This must include whitespace round all elements and
their counts, which must be explicit.
                </p>
            </div>
            <div class="example">
                <pre>
<cml title="formula example">
<molecule id="sulfuricAcid">
<formula concise="H 2 S 1 O 4"/>
</molecule>
<molecule id="CuprammoniumSulfate">
<formula title="[Cu(NH3)4]2+ SO42-]">
<formula formalCharge="+2">
<atomArray elementType="Cu"/>
<formula count="4">
<atomArray elementType="N H" count="1 3"/>
</formula>
</formula>
<formula formalCharge="-2">
<atomArray elementType="S O" count="1 4"/>
</formula>
</formula>
</molecule>
</cml>
                </pre>
            </div>
        </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
        <xsd:choice>
            <xsd:choice minOccurs="0" maxOccurs="unbounded">
                <xsd:element ref="formula"/>
                <xsd:element ref="atomArray"/>
            </xsd:choice>
        </xsd:choice>
        <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
        <xsd:attribute name="count" type="positiveNumberType">
            <xsd:annotation>
                <xsd:documentation>
                    <div class="summary">A multiplier for the formula.</div>
                    <div class="description">No formal default but assumed to be 1. Allows for fractional components.</div>
                </xsd:documentation>
            </xsd:annotation>
        </xsd:attribute>
        <xsd:attribute name="formalCharge" type="xsd:integer">
            <xsd:annotation>
                <xsd:documentation>
                    <p>
The formal charge is normally calculated from the formal charges of the
atoms. If the
                        <tt>formalCharge</tt>
attribute is given it overrides this
information completely. This allows (say) metal complexes to be represented
when it is difficult to apportion the charges to atoms.
                    </p>
                </xsd:documentation>
            </xsd:annotation>
        </xsd:attribute>
        <xsd:attribute name="concise" type="formulaType">
            <xsd:annotation>
                <xsd:documentation>
                    <div class="summary">A concise string representing an (unstructured) formula.</div>
                </xsd:documentation>
            </xsd:annotation>
        </xsd:attribute>
    </xsd:complexType>
</xsd:element>

It is defined by atomArrays each with a list of elementTypes and their counts (or default=1). All other information in the atomArray is ignored. formula are nestable so that aggregates (e.g. hydrates, salts, etc.) can be described. CML does not require that formula information is consistent with (say) crystallographic information; this allows for experimental variance.

An alternative briefer representation is also available through the conciseForm. This must include whitespace round all elements and their counts, which must be explicit.

element {http://www.xml-cml.org/schema/cml2/core}formula

Source

Documentation