The schema for CDISC ODM, as implemented natively by OpenClinica (ODM 1.3, including vendor extensions) can be found at https://dev.openclinica.com/tools/odm-doc/. This page provides an overview of the schemas/namespaces that are used in an OpennClinica ODM document. Click on the ‘schema location’ for each individual schema to get the raw XSD. You can also see a visualization of the data structures here.