The luminescence of silver(I) ions was investigated in diphosphate of compo
sitions Na2-xAgxZnP2O7. The [P2O7] groups share corners with [ZnO4] tetrahe
dra in a layer arrangement. The Na/Ag atoms are located between layers in d
istorted oxygenated cubic sites sharing faces-with short intermetallic dist
ances-or edges. Two luminescent centers were detected and attributed, respe
ctively, to single Ag+ and Ag+-Ag+ pairs. The luminescent parameters are di
scussed with respect to the symmetry of the silver sites and of the ionocov
alent character of the silver oxygen bonds. (C) 2000 Academic Press.