The NIST Chemistry WebBook provides users with easy access to chemical and physical property data for chemical species through the internet. The data provided in the site are from collections maintained by the NIST Standard Reference Data Program and outside contributors. Data in the WebBook system are organized by chemical species. The WebBook system allows users to search for chemical species by various means. Once the desired species has been identified, the system will display data for the species. Data include thermochemical properties of species and reactions, thermophysical properties of species, and optical, electronic and mass spectra.

This database provides access and search capability for NIST critically evaluated data on atomic energy levels, wavelengths, and transition probabilities that are reasonably up-to-date. The Atomic Spectroscopy Data Center has carried out these critical compilations. The Data Center is located in the Physical Measurement Laboratory at the National Institute of Standards and Technology (NIST).

This database contains the rotational spectral lines observed and reported in the open literature for 91 hydrocarbon molecules through September 1987. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty and reference are given for each transition reported. In addition to correcting a number of misprints and errors in the literature cited, the spectral lines for many normal isotopic species have been refit to produce a comprehensive and consistent analysis of all the data extracted from various literature sources. The derived molecular properties, such as rotational and centrifugal distortion constants, hyperfine structure constants, electric dipole moments, and rotational g-factors are listed.

This interactive database, maintained by the NIST Atomic Spectroscopy Data Center, contains more than 6000 references, dating from 1889 through current year and is updated regularly in intervals between one and four weeks. These references pertain to publications that include numerical data, general information, comments, and reviews on atomic line broadening and shifts.

The Nuclear Magnetic Resonance Spectral Measurement Database (NMR-SMDB) was developed for the purpose of organizing and searching NMR spectral data of protein therapeutics, linking spectra to corresponding sample information and enabling quick access to full datasets and entire studies. In addition to supporting internal NIST research, the system could facilitate data access to stakeholders outside of NIST, and future versions of the database software itself could be installed by others for their own data storage and retrieval.

description: References contained in this database are from Bibliography on Atomic Energy Levels and Spectra, NBS Special Publication 363 and Supplements, as well as current references since the last published bibliography collected by the NIST Atomic Spectroscopy Data Center (http://www.nist.gov/physlab/div842/grp01/asdc_info.cfm). These references pertain to atomic structure and spectra that arise from interactions or excitations involving electrons in the outer shells of free atoms and atomic ions, or from inner shell excitations corresponding to frequencies up to the soft x-ray range. Please note that this database does not contain references to atomic transition probabilities, line intensities, or broadening. These references can be found in two other bibliographic databases maintained by the same Data Center: NIST Atomic Transition Probability Bibliographic Database (http://physics.nist.gov/fvalbib) and NIST Atomic Spectral Line Broadening Bibliographic Database (http://physics.nist.gov/linebrbib). References to publications containing critically compiled data can be found in a separate database of NIST compilations of atomic spectroscopy data (http://physics.nist.gov/PhysRefData/datarefs/datarefs_search_form.html).; abstract: References contained in this database are from Bibliography on Atomic Energy Levels and Spectra, NBS Special Publication 363 and Supplements, as well as current references since the last published bibliography collected by the NIST Atomic Spectroscopy Data Center (http://www.nist.gov/physlab/div842/grp01/asdc_info.cfm). These references pertain to atomic structure and spectra that arise from interactions or excitations involving electrons in the outer shells of free atoms and atomic ions, or from inner shell excitations corresponding to frequencies up to the soft x-ray range. Please note that this database does not contain references to atomic transition probabilities, line intensities, or broadening. These references can be found in two other bibliographic databases maintained by the same Data Center: NIST Atomic Transition Probability Bibliographic Database (http://physics.nist.gov/fvalbib) and NIST Atomic Spectral Line Broadening Bibliographic Database (http://physics.nist.gov/linebrbib). References to publications containing critically compiled data can be found in a separate database of NIST compilations of atomic spectroscopy data (http://physics.nist.gov/PhysRefData/datarefs/datarefs_search_form.html).

This handbook provides a selection of the most important and frequently used atomic spectroscopic data in an easily accessible format. The compilation includes energy levels, ionization energies, wavelengths, line intensities, transition probabilities, and spectrum assignments for the neutral and singly-ionized atoms of all elements hydrogen through einsteinium (Z = 1-99), given in separate tables for each element. It includes approximately 12,000 spectral lines of all elements. Bibliographic references are provided for all data.

The NIST DART-MS Forensics Database is an evaluated collection of in-source collisionally-induced dissociation (is-CID) mass spectra of compounds of interest to the forensics community (e.g. seized drugs, cutting agents, etc.). The is-CID mass spectra were collected using Direct Analysis in Real-Time (DART) Mass Spectrometry (MS), either by NIST scientists or by contributing agencies noted per compound. The database is provided as a general-purpose structure data file (.SDF). For users on Windows operating systems, the .SDF format library can be converted to NIST MS Search format using Lib2NIST and then explored using NIST MS Search v2.4 for general mass spectral analysis. These software tools can be downloaded at https://chemdata.nist.gov. The database is now (09-28-2021) also provided in R data format (.RDS) for use with the R programming language. This database, also commonly referred to as a library, is one in a series of high-quality mass spectral libraries/databases produced by NIST (see NIST SRD 1a, https://dx.doi.org/10.18434/T4H594).

Data here contain and describe an open-source structured query language (SQLite) portable database containing high resolution mass spectrometry data (MS1 and MS2) for per- and polyfluorinated alykl substances (PFAS) and associated metadata regarding their measurement techniques, quality assurance metrics, and the samples from which they were produced. These data are stored in a format adhering to the Database Infrastructure for Mass Spectrometry (DIMSpec) project. That project produces and uses databases like this one, providing a complete toolkit for non-targeted analysis. See more information about the full DIMSpec code base - as well as these data for demonstration purposes - at GitHub (https://github.com/usnistgov/dimspec) or view the full User Guide for DIMSpec (https://pages.nist.gov/dimspec/docs).Files of most interest contained here include the database file itself (dimspec_nist_pfas.sqlite) as well as an entity relationship diagram (ERD.png) and data dictionary (DIMSpec for PFAS_1.0.1.20230615_data_dictionary.json) to elucidate the database structure and assist in interpretation and use.

GC-MS Database NIST/EPA/NIH MASS SPECTRAL LIBRARY (NIST 08) + update 2010 2.0f Apr 1 2009 x86 [2008, ENG] This library package contains the NIST 2008 Mass Spectral Library in the following manufacturer formats: 1. Agilent Chemstation (.L) (with structures) 2. NIST MS Search (compatible with most mass spectrometry software brands): Bruker; JEOL; LECO; PerkinElmer TurboMass; Thermo Electron XCalibur; Varian MS Workstation; Waters MassLynx; and other brands 3. PerkinElmer TurboMass (IDB) (with structures) 4. Shimadzu GCMS Solution (QP5000) (SPC) (no structures) 5. Waters MassLynx (IDB) (with structures) 6. Finnigan GCQ/Varian ITS-40 7. Thermo Galactic Spectral ID Includes: - Over 220,000 spectra, - Over 190,000 chemical structures, and - GC Retention Index Library, MS/MS Library - Licenses keys

NIST peptide libraries are comprehensive, annotated mass spectral reference collections from various organisms and proteins useful for the rapid matching and identification of acquired MS/MS spectra. Spectra were produced by tandem mass spectrometers using liquid chromatographic separations followed by electrospray ionization. Unlike the NIST small molecule electron ionization library which contains one spectrum per molecular structure, there are several different modes of fragmentation (ion trap and ?beam-type? collision cells are currently the most commonly used fragmentation devices) that result in spectra with different, energy dependent, patterns. These result in multiple spectral libraries, distinguished by ionization mode, each of which may contain several spectra per peptide. Different libraries have also been assembled for iTRAQ-4 derivatized peptides and for phosphorylated peptides. Separating libraries by animal species reduces search time, although investigators may elect to include several species in their searches.

This data base contains the rotational spectral lines observed and reported in the open literature for 55 triatomic molecules through June 1976. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty and reference are given for each transition reported. In addition to correcting a number of misprints and errors in the literature cited, the spectral lines for approximately 15 molecules have been refit to produce a comprehensive and consistent analysis of all the data extracted from various literature sources. Both measured and predicted transition frequencies are listed for several isotopic forms of HCN, H2O, H2S, and OCS. The derived molecular properties, such as rotational and centrifugal distortion constants, hyperfine structure constants, electric dipole moments, and rotational g-factors are listed with one standard deviation uncertainty for all values.

This database is the product of a multi-year, comprehensive evaluation and expansion of the world's most widely used mass spectral reference library.

This dataset contains information regarding the development of targeted GC-MS methods for forensic seized drug analysis. Included in this dataset are method parameter files, mass spectra, mass spectral databases, and retention time / retention index data.

This data set contains the spectral data associated with the collection of EC-SERS spectra using mainly a nontargeted drug identification approach, with several samples using a targeted fentanyl identification approach. The data set contains the replicate measurements and averaged Raman spectra used in the characterization of the analytes (drugs of abuse and adulterant compounds) to allow for forensic library formation. The data set also contains spectra of analytes collected at varying concentrations and additional fentanyl analog data collected using a targeted method.

Direct Analysis in Real Time Mass Spectrometry (DART-MS) is an analytical chemistry technology that is being increasingly employed in forensic applications. This form of mass spectrometry rapidly yields rich structural information about an analyte with minimal sample preparation. The challenge with DART-MS data, much like other data generated with high throughput technologies, lies in the data interpretation. This is especially true when the analyzed samples are multi-component mixtures like seized drug evidence. The NIST/NIJ DART-MS Data Interpretation Tool (DIT) is a freely available and open-source software tool developed to support the interpretation of in-source collision induced dissociation (is-CID) DART-MS data. The NIST/NIJ DART-MS DIT can be used to view reference mass spectra from DART-MS spectral libraries, search query DART-MS mass spectra of mixtures against reference libraries, using the Inverted Library Search Algorithm, and generate printable reports from search results. Several of the features, including the formatting of generated reports, were iteratively designed with input from local, state, and federal forensic practitioners, ensuring that the program is intuitive and usable for the expected users.

This database is the product of a multi-year, comprehensive evaluation and expansion of the world's most widely used mass spectral reference library.

This database contains critically evaluated transition frequencies for the molecular transitions detected in interstellar and circumstellar clouds reported in the literature through mid-2008. The tabulated transition frequencies are recommended for reference in future astronomical observations in the centimeter and millimeter wavelength regions. The transition frequencies have been selected through a critical examination and analysis of the laboratory spectral data obtained from the literature. The information tabulated includes the species identity, transition frequency, uncertainty, and quantum state labels. For convenience, representative line antenna temperatures are listed for a typical astronomical source for each transition, and the references are cited for the laboratory and astronomical literature that have been employed. 2009 Revision

The NIST Chemical Kinetics Database includes essentially all reported kinetics results for thermal gas-phase chemical reactions. The database is designed to be searched for kinetics data based on the specific reactants involved, for reactions resulting in specified products, for all the reactions of a particular species, or for various combinations of these. In addition, the bibliography can be searched by author name or combination of names. The database contains in excess of 38,000 separate reaction records for over 11,700 distinct reactant pairs. These data have been abstracted from over 12,000 papers with literature coverage through early 2000. Rate constant records for a specified reaction are found by searching the Reaction Database. All rate constant records for that reaction are returned, with a link to 'Details' on that record. Each rate constant record contains the following information (as available): a) Reactants and, if defined, reaction products; b) Rate parameters: A, n, Ea/R, where k = A (T/298)*n exp[-(Ea/R)/T], where T is the temperature in Kelvins; c) Uncertainty in A, n, and Ea/R, if reported; d) Temperature range of experiment or temperature range of validity of a review or theoretical paper; e) Pressure range and bulk gas of the experiment; f) Data type of the record (i.e., experimental, relative rate measurement, theoretical calculation, modeling result, etc.). If the result is a relative rate measurement, then the reaction to which the rate is relative is also given; g) Experimental procedure, including separate fields for the description of the apparatus, the time resolution of the experiment, and the excitation technique. A majority of contemporary chemical kinetics methods are represented. The Kinetics Database is being expanded to include other resources for the convenience of the users. Presently this includes direct links to the corresponding NIST WebBook page for all substances for which such a link is possible. This is indicated by underling and highlighting the species. The WebBook provides thermodynamic, spectral, and other data on the species. Note that the link to the WebBook is opened as a new frame in your browser.

This is the data underlying "Sub-Doppler spectroscopy of quantum systems through nanophotonic spectral translation of electro-optic light" https://arxiv.org/abs/2309.16069 which is to be published in Nature Photonics.