formulaType

<xsd:simpleType name="formulaType" id="st.formulaType">
  <xsd:annotation>
    <xsd:documentation>
      <h:div class="summary">A concise representation for a molecular formula.</h:div>
      <h:div class="description">This MUST adhere to a whitespaced syntax so that it is trivially machine-parsable. Each element is followed by its count (which may be decimal), and the string is optionally ended by a formal charge (of form d or -d, i.e. no '+') NO brackets or other nesting is allowed.</h:div>
      <h:div class="example" href="formulaType1.xml"/>
      <h:div class="curation">2005-08-30: allowed decimal points</h:div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:restriction base="xsd:string">
    <xsd:pattern value="\s*([A-Z][a-z]?\s+(([0-9]+(\.[0-9]*)?)|(\.[0-9]*))?\s*)+(\s+[\-]?[0-9]+)?\s*"/>
  </xsd:restriction>
</xsd:simpleType>