From the editor in chief

Tilting structures in spinels

“…The polyhedral groups of atoms, units (fragments, modules, structural blocks) resistant to external impact, are well known in structural chemistry, crystal chemistry and solid-state physics (Pauling, 1967;Belov, 1947;Urusov, 1987). The modular structure is found in alloys (O'Keeffe & Andersson, 1977), polyphosphides (Jeitschko & Braun, 1978), silicates (Thompson, 1978;Horiuchi et al, 1980), spinelloids (Horioka et al, 1981;Ivanov & Talanov, 2008) and other families of substances (Wells, 1987(Wells, -1988Ormont, 1950;Pearson, 1977;Hazen & Finger, 1981;Talanov et al, 2008;Zvyagin, 1993;Blatov et al, 1994;Shevchenko et al, 2009;Zheligovskaya & Bulenkov, 2008a,b;Ferey, 2000). Today it is clear that the modular structure of matter is a universal feature of matter at all structural levels (Ivanov & Talanov, 2010a,b,c;Ferraris et al, 2005).…”

“…There have been many approaches to solving this problem (see e.g. Zvyagin, 1993;Blatov et al, 1994;Shevchenko et al, 2009;Zheligovskaya & Bulenkov, 2008a,b;Ferey, 2000;Ivanov & Talanov, 2010a,b,c;Ferraris et al, 2005;Dornberger-Schiff, 1964;Talis & Koptsik, 1990;Burdett, 1980;Glazer, 1972Glazer, , 1975Woodward, 1997a,b;Bock & Mü ller, 2002). We select group-theoretic methods as the most accurate for the listing of new structures (Gufan, 1982).…”