High-energy X-ray diffraction, neutron diffraction and extended X-ray absorption fine structure experiments have been carried out for (MI)(x) (As2Se3)(1-x) glasses (M: Ag or Cu). The addition of a large amount of MI does not significantly affect short-range orderings of the host network matrix. The interatomic distance of M-I pairs is very similar to the case of crystalline MI. However, the coordination number of M-I pairs in the present glasses seems to be somewhat smaller than that in the crystalline MI, suggesting a heavy distortion of tetrahedral coordinates of MI units or structural disorder of the I-I sub-cages in the glass state. It would be predictable that the structure model for MI-As2Se3 glasses is proposed to be a pseudobinary mixture of the As(Se-1/2)(3) network matrix and MI-related conduction pathways. (c) 2006 Elsevier B.V. All rights reserved.