Utilities

Diffuse Data Format Converter

A browser-based converter for 3-D single-crystal diffuse scattering data. It translates the same intensity grid between the file formats used by RMCProfile, DISCUS, Yell, Meerkat, and Scatty, entirely inside the browser. No installation, no server, and no upload: files never leave your computer.

Start Here

• Live Tool
• Or open Format_Converter.html locally in any modern browser (double-click works; no web server is needed).

Supported Formats

Format	Read	Write	Typical producer
Unified data format (HDF5)	yes	yes	RMCProfile, DiffuseCode/DISCUS
Yell 1.0 (HDF5)	yes	yes	DISCUS, Yell, Meerkat
RMCProfile old text format (.dat)	yes	yes	RMCProfile Diffuse3D
Scatty VTK (.vtk)	yes	yes	Scatty; also loads in ParaView

Any format can be converted to any other. The input format is detected automatically from the file content.

Format notes

• Unified data format: both the /scattering/data compatibility layout and the RMCProfile/DISCUS /entry/data layout are read; written files contain both. New output follows the current common contract: the mandatory crystal-metadata audit datasets are written under /entry/data, with audit_conform_dict_name = Disorder unified data, data_type_axes = hkl, and data_type_number = real. Readers accept the older Disorder scattering name and infer missing axes metadata as RMCProfile does for legacy files, but reject a structure dictionary or an unsupported axes/number type instead of silently treating it as HKL data. Three-dimensional Q axes are converted to HKL using the real parent cell; scalar or direct-space axis types are outside this diffuse converter. Optional crystal flags do not control diffuse-grid interpretation; the standard cell and symmetry fields are always written.
• Yell 1.0: the flat layout with /data, /lower_limits, /step_sizes, and /unit_cell datasets. Files that store the unit metric (unit_cell = 1 1 1 90 90 90) are interpreted as hkl grids in reciprocal lattice units of the parent cell; written files always store the real cell when one is known.
• RMCProfile old text format: an npoints nsec header followed by i j k qx qy qz intensity rows. Q is cartesian in 1/Angstrom with the 2*pi convention, q = 2*pi * B * hkl, where B is the reciprocal basis of the parent cell. Files with several symmetry sections are read using the section 1 coordinates.
• Scatty VTK: ASCII STRUCTURED_POINTS as written by Scatty. ORIGIN and SPACING are cartesian Q in 1/Angstrom (2*pi convention, the same as the old text format); values run x fastest, z slowest. Writing VTK requires the Q grid to be axis-aligned and ascending, because STRUCTURED_POINTS cannot express rotated or non-orthogonal grids (Scatty itself has the same restriction).

Usage

1. Data file: select the diffuse data file (.h5, .dat, or .vtk). The format, grid size, and stored cell are reported in the log.
2. Unit cell: some conversions need the parent (crystallographic) unit cell, because the text and VTK formats do not store one, and some Yell files store only the unit metric. Provide either
   • a structure file: .rmc6f or unified structure .h5. For .rmc6f, the parent cell is the supercell divided by its dimensions. In the unified structure contract, unit_cell_lengths already stores the basic/parent cell and is used directly; or
   • the parent cell typed in directly (a, b, c in Angstrom; alpha, beta, gamma in degrees). When the data file already stores a real cell (for example RMCProfile _calc.h5 output), it is used automatically and this section can be left empty.
3. Output: pick the target format, optionally set the radiation metadata for HDF5 output, and press “Convert and download”.

When is the unit cell required?

Input	Cell needed?
Unified .h5 with a real cell	no
Yell .h5 with a real cell	no
Yell .h5 with unit metric	yes (for .dat/.vtk output; passed through for HDF5 output)
Old text .dat	yes, always
Scatty .vtk	yes, always

Examples

The Examples/ folder contains one small synthetic dataset (cubic parent cell a = 5.63 Angstrom, 5 x 5 x 5 grid, hkl from -1 to 1 in steps of 0.5) written in every supported format, plus a matching structure file:

• example_structure.rmc6f - structure with a 2 x 2 x 2 supercell
• example_unified.h5 - unified data format
• example_yell.h5 - Yell 1.0
• example_diffuse3d.dat - RMCProfile old text format
• example_scatty.vtk - Scatty VTK

Load any of the data files, add example_structure.rmc6f where a cell is required, and convert in any direction; the intensity values are identical in all files, so results are easy to compare.

Included Surface

• Format_Converter.html
  • Main browser app.
• js/converter.js
  • Format readers/writers and the cell/reciprocal-space math. Plain JavaScript, also loadable from Node.js for testing.
• js/h5wasm.js
  • Vendored h5wasm 0.10.3 bundle (the HDF5 library compiled to WebAssembly, self-contained). License in js/h5wasm-LICENSE.txt.
• Examples/
  • The example dataset described above.

Validation

The conversion core was verified against real files from each producer:

• Yell/DISCUS: a DISCUS-written Yell 1.0 file converts to the RMCProfile old text format reproducing an independently produced reference .dat for the same dataset at the reference file’s own precision.
• Scatty: parsing a Scatty .vtk reproduces the intensities of Scatty’s paired *_list.txt hkl output exactly, and the recovered hkl grid matches it to the 6-decimal precision of the VTK header.
• RMCProfile: HDF5 files written by the converter follow the same dataset layouts, mandatory audit/type metadata, axis ordering, and fixed-length string types as RMCProfile’s Fortran implementation (unified_config/unified_hdf5_io.f90), and round-trip conversions through every format are exact at double precision.

Command-Line Equivalents

RMCProfile (built with RMC_ENABLE_HDF5=ON) provides Fortran tools for the unified/old-text conversions: unified_to_diffuse3d and diffuse3d_to_unified.

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