symbolic array lengths to be coordinated between various fields number of compositions number of temperatures number of values in applied electric field number of values in applied magnetic field number of values in applied pressure field number of values in applied stress field Any information on the sample. This could include scanned variables that are associated with one of the data dimensions, e.g. the magnetic field, or logged data, e.g. monitored temperature vs elapsed time. Descriptive name of sample The chemical formula specified using CIF conventions. Abbreviated version of CIF standard: * Only recognized element symbols may be used. * Each element symbol is followed by a 'count' number. A count of '1' may be omitted. * A space or parenthesis must separate each cluster of (element symbol + count). * Where a group of elements is enclosed in parentheses, the multiplier for the group must follow the closing parentheses. That is, all element and group multipliers are assumed to be printed as subscripted numbers. * Unless the elements are ordered in a manner that corresponds to their chemical structure, the order of the elements within any group or moiety depends on whether or not carbon is present. * If carbon is present, the order should be: - C, then H, then the other elements in alphabetical order of their symbol. - If carbon is not present, the elements are listed purely in alphabetic order of their symbol. * This is the *Hill* system used by Chemical Abstracts. Sample temperature. This could be a scanned variable Applied electric field Applied magnetic field Applied external stress field Applied pressure Sample changer position Crystallography unit cell parameters a, b, and c Crystallography unit cell parameters alpha, beta, and gamma Unit cell parameters (lengths and angles) Volume of the unit cell This will follow the Busing-Levy convention: W. R. Busing and H. A. Levy (1967). Acta Cryst. 22, 457-464 Orientation matrix of single crystal sample using Busing-Levy convention: W. R. Busing and H. A. Levy (1967). Acta Cryst. 22, 457-464 UB matrix of single crystal sample using Busing-Levy convention: W. R. Busing and H. A. Levy (1967). Acta Cryst. 22, 457-464. This is the multiplication of the orientation_matrix, given above, with the :math:`B` matrix which can be derived from the lattice constants. Mass of sample Density of sample Relative Molecular Mass of sample The atmosphere will be one of the components, which is where its details will be stored; the relevant components will be indicated by the entry in the sample_component member. Description of the sample Date of preparation of the sample The position and orientation of the center of mass of the sample Details of beam incident on sample - used to calculate sample/beam interaction point One group per sample component This is the perferred way of recording per component information over the n_comp arrays Details of the component of the sample and/or can Type of component Concentration of each component Volume fraction of each component Scattering length density of each component In case it is all we know and we want to record/document it Crystallographic space group Crystallographic point group, deprecated if space_group present Path length through sample/can for simple case when it does not vary with scattering direction Thickness of a beam entry/exit window on the can (mm) - assumed same for entry and exit sample thickness As a function of Wavelength temperature_log.value is a link to e.g. temperature_env.sensor1.value_log.value Additional sample temperature environment information magnetic_field_log.value is a link to e.g. magnetic_field_env.sensor1.value_log.value Additional sample magnetic environment information value sent to user's sample setup logged value (or logic state) read from user's setup 20 character fixed length sample description for legends Optional rotation angle for the case when the powder diagram has been obtained through an omega-2theta scan like from a traditional single detector powder diffractometer Translation of the sample along the X-direction of the laboratory coordinate system Translation of the sample along the Z-direction of the laboratory coordinate system Any positioner (motor, PZT, ...) used to locate the sample