It is necessary to follow certain basic syntax rules concerning the formula sum in order to enable Match! to extract the elements properly. This dialog is displayed if Match! discovers an error in the formula sum.
Please use upper and lower case characters in the element symbols, like in "Ca Si O3" (do not use "ca si o3" or "CA SI O3").
In addition, it is strongly recommended to enter the formula sum according to the PDF or CIF syntax rules. The most important point is to insert a blank (space) character between two elements, e.g. "Mg2 Si O4" (and not "Mg2SiO4") or "Cu S O4 (H2 O)5" (and not "CuSO4(H2O)5").