<xsd:element name="peakGroup" id="el.peakGroup">
    <xsd:annotation>
        <xsd:documentation>
            <h:div class="summary" xmlns:h="http://www.w3.org/1999/xhtml">A list of closely related peaks or peakGroups.</h:div>
            <h:div class="description" xmlns:h="http://www.w3.org/1999/xhtml">Distinguish between <h:tt>peakList</h:tt> (primarily a navigational container) and <h:tt>peakGroup</h:tt> where the peaks (or groups) have some close relation not shared by all peaks. All descendants must use consistent units.</h:div>
            <h:div class="curation" xmlns:h="http://www.w3.org/1999/xhtml">2005-11-22. added atomRefs, bondRefs and moleculeRefs and deprecated 
            atom, bond, molecule children</h:div>
            <h:div class="example" href="peakGroup1.xml" xmlns:h="http://www.w3.org/1999/xhtml" />
        </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
        <xsd:sequence>
            <xsd:element ref="metadataList" minOccurs="0">
                <xsd:annotation>
                    <xsd:documentation>
                        <h:div class="summary" xmlns:h="http://www.w3.org/1999/xhtml">Allows <h:i>inter alia</h:i> the provenance of the peak assignment to be recorde.</h:div>
                    </xsd:documentation>
                </xsd:annotation>
            </xsd:element>
            <xsd:choice minOccurs="0" maxOccurs="unbounded">
                <xsd:element ref="peak" />
                <xsd:element ref="peakGroup" />
                <xsd:element ref="atom">
                    <xsd:annotation>
                        <xsd:documentation>
                            <h:div class="curation" xmlns:h="http://www.w3.org/1999/xhtml">2005-11-22. DEPRECATED; use atomRefs</h:div>
                        </xsd:documentation>
                    </xsd:annotation>
                </xsd:element>
                <xsd:element ref="bond">
                    <xsd:annotation>
                        <xsd:documentation>
                            <h:div class="curation" xmlns:h="http://www.w3.org/1999/xhtml">2005-11-22. DEPRECATED; use bondRefs</h:div>
                        </xsd:documentation>
                    </xsd:annotation>
                </xsd:element>
                <xsd:element ref="molecule">
                    <xsd:annotation>
                        <xsd:documentation>
                            <h:div class="curation" xmlns:h="http://www.w3.org/1999/xhtml">2005-11-22. DEPRECATED; use moleculeRefs</h:div>
                        </xsd:documentation>
                    </xsd:annotation>
                </xsd:element>
            </xsd:choice>
        </xsd:sequence>
        <xsd:attributeGroup ref="dictRef" />
        <xsd:attributeGroup ref="convention" />
        <xsd:attributeGroup ref="title" />
        <xsd:attributeGroup ref="id" />
        <xsd:attributeGroup ref="ref" />
        <xsd:attributeGroup ref="peakHeight" />
        <xsd:attributeGroup ref="peakMultiplicity" />
        <xsd:attributeGroup ref="peakShape" />
        <xsd:attributeGroup ref="integral" />
        <xsd:attributeGroup ref="peakUnits" />
        <xsd:attributeGroup ref="xMin" />
        <xsd:attributeGroup ref="xMax" />
        <xsd:attributeGroup ref="xValue" />
        <xsd:attributeGroup ref="xWidth" />
        <xsd:attributeGroup ref="xUnits" />
        <xsd:attributeGroup ref="yMin" />
        <xsd:attributeGroup ref="yMax" />
        <xsd:attributeGroup ref="yValue" />
        <xsd:attributeGroup ref="yWidth" />
        <xsd:attributeGroup ref="yUnits" />
        <xsd:attributeGroup ref="atomRefs">
            <xsd:annotation>
                <xsd:documentation>
                    <h:div class="summary" xmlns:h="http://www.w3.org/1999/xhtml">Atoms contributing to this peak</h:div>
                    <h:div class="description" xmlns:h="http://www.w3.org/1999/xhtml">The primary set of atoms responsible for
		            the peak such as an NMR peak. Coupling constants and similar splitting
		            should not use this but peakStructure. At present there is no substructure to this
		            attribute or concept and only one attribute is allowed. It may be
		            combined with bondRefs. Even single atoms should use atomRefs, not atomRef.
		            </h:div>
                </xsd:documentation>
            </xsd:annotation>
        </xsd:attributeGroup>
        <xsd:attributeGroup ref="bondRefs">
            <xsd:annotation>
                <xsd:documentation>
                    <h:div class="summary" xmlns:h="http://www.w3.org/1999/xhtml">Bonds contributing to this peak</h:div>
                    <h:div class="description" xmlns:h="http://www.w3.org/1999/xhtml">The primary set of bonds responsible for
		            the peak such as an IR frequency. At present there is no substructure to this
		            attribute or concept and only one attribute is allowed. It may be
		            combined with atomRefs.</h:div>
                </xsd:documentation>
            </xsd:annotation>
        </xsd:attributeGroup>
        <xsd:attributeGroup ref="moleculeRefs">
            <xsd:annotation>
                <xsd:documentation>
                    <h:div class="summary" xmlns:h="http://www.w3.org/1999/xhtml">Molecule(s) contributing to this peak</h:div>
                    <h:div class="description" xmlns:h="http://www.w3.org/1999/xhtml">The molecule or molecule responsible for
		            the peak. At present there is no substructure to this
		            attribute or concept and only one attribute is allowed. This might, for example,
		            be used to manage a mass spectrum or chromatogram</h:div>
                </xsd:documentation>
            </xsd:annotation>
        </xsd:attributeGroup>
    </xsd:complexType>
</xsd:element>