nmrML

nmrML is an open, XML-based data standard for representing nuclear magnetic resonance (NMR) spectroscopy data and associated metadata. It is designed to enable comprehensive storage, sharing, and reanalysis of NMR experiments across software platforms and databases, supporting reproducibility and data integration in metabolomics and related fields.

The standard covers both experimental metadata and spectral data. It provides a framework to describe samples, instruments, pulse sequences, acquisition parameters, chemical references, and experimental conditions. In addition, nmrML can capture processed data such as spectra, peak lists, chemical shifted values, intensities, and peak assignments, along with details of data processing steps (for example, apodization, baseline correction, and referencing). It is capable of representing one-dimensional and multidimensional experiments (for example, 1D 1H/13C and common 2D experiments), as well as the associated metadata necessary for interpretation and reuse.

Format and structure are defined by an XML schema (XSD). A typical nmrML file encodes information in modular sections, including nomenclature for instruments, samples, spectra, peak lists, and binary data arrays that store the actual spectral data. The schema is designed to be extensible and to support controlled vocabularies and ontologies for consistent description of parameters and units.

nmrML aims to promote interoperability with other data standards in metabolomics, such as mzML for mass spectrometry, and to facilitate deposition to public repositories and cross-platform data exchange. It is maintained by a community-driven consortium and is openly available for adoption and contribution. Related standards include NMR-STAR and other community annotations used in NMR data management.