HPDF: High Pressure Diffraction File Format

HPDF (High Pressure Diffraction File) files, formerly known in high-pressure research community as JCPDS files allow storing information about the crystal structure, diffraction pattern, and thermoelastic behavior of crystalline materials in plain text ASCI format.

Links

Here is a link to the COMPTECH JCPDS card website created by Bin Chen: COMPTECH JCPDS

Dan Shim group's JCPDS repo (certified internally by the group): Shim group's JCPDS database

Here is a link to the IDL JCPDS class library created by Mark Rivers: IDL JCPDS class library

Here is a link to the current JCPDS version 4 keyword dictionary: Keyword dictionary

Description and Rules of the HPDF format

• Each line of the HPDF file starts with a keyword, which is a string up to 8 upper case characters, terminated with a colon.
• The keywords typically define type of parameter characterizing given material, however, there are also special keywords, e.g. describing version of the HPDF file (VERSION:), allowing to include comments (COMMENT:), etc.
• The keyword is followed by a parameter value, which can be numeric or string type.
• Some parameters/keywords require multiple numeric values (array of numbers). An example of this is DIHKL: which in JCPDS version 4 requires 5 numeric values corresponding to d-spacing, intensity and three hkl indices.
• Keyword names do not use special characters.
• Lines that do not start with a keyword are ignored.