AN IDENTIFICATION SYSTEM USING CHEMICAL INFORMATION IN MODIFIED EXISTING DATABASES. A.R. Hölzel, Systematik in der Mineralogie D-55270 Ober-Olm, Ulmenring 11, Germany

A computer program package is developed to identify inorganic phases or metal organic complexes using quantitative chemical analysis data. Crystal-chemical terms allow the search for variable compositions within solid solution series or related compounds. The use in combination with other parameters, e.g. X-ray, crystal-data, etc. is possible.

The database contains the chemical composition and crystal-chemical terms by weight- and atom-%, mostly derived from the sum formula using existing databases. The grouping of the crystal-chemical terms is based on:

1. The periodical table of the elements, Group 1Aa to 8Bb - H,(D,T) to Platin Group Elements with subdivisions depending on chemical behavior or ionic radii, e.g. group 1A splits into 1Aa=H,D, and T; 1Ab=Li; 1Ac=Na to Fr,

2. Three additional Groups, containing only micro- probe detectable elements, here defined by Na and all elements of higher atomic weight. <L> to the large and <M> to the medium to small cation radii elements. <E> collects all micro-probe detectable elements. These group symbols will be handled like element symbols.

E.g. a description by wt.-% of a compound like NaAl[SO₄]₂*12H₂O: Na--5.02 Al--5.89 S-13.98O-69.84 H--5.28 1Ac--5.02 3Ab--5.89 6Ab-13.981Aa--5.28 6Aa-69.84 L--5.02 M--5.89 E-24.89.

A search using analysis data with intervals will find this compound, a similar search with atom-% will find the whole family.