<i>QUALX2.0</i>: a qualitative phase analysis software using the freely available database POW_COD

QUALX2.0 is the new version of QUALX , a computer program for qualitative phase analysis by powder diffraction data. The previous version of QUALX was able to carry out phase identification by querying the PDF-2 commercial database. The main novelty of QUALX2.0 is the possibility of querying also a freely available database, POW_COD. POW_COD has been built up by starting from the structure information contained in the Crystallography Open Database (COD). The latter is a growing collection of diffraction data, freely downloadable from the web, corresponding to inorganic, metal–organic, organic and mineral structures. QUALX2.0 retains the main capabilities of the previous version: ( a ) automatically estimating and subtracting the background; ( b ) locating the experimental diffraction peaks; ( c ) searching the database for single-phase pattern(s) best matching to the experimental powder diffraction data; ( d ) taking into account suitable restraints in the search; ( e ) performing a semi-quantitative analysis; ( f ) enabling the change of default choices and strategies via a user-friendly graphic interface. The advances of QUALX2.0 with respect to QUALX include (i) a wider variety of types of importable ASCII file containing the experimental diffraction pattern and (ii) new search–match options. The program, written in Fortran and C++, runs on PCs under the Windows operating system. The POW_COD database is exported in SQLite3 format.