Using extended X-ray absorption fine structure (EXAFS) spectroscopy, we find that Cr substitutes primarily in the Li+ site as a dopant in lithium tetraborate Li2B4O7 glasses, in this case 98.4Li(2)B(4)O(7)-1.6Cr(2)O(3) or nominally Li1.98Cr0.025B4O7. This strong preference for a single site is nonetheless accompanied by site distortions and some site disorder, helping explain the optical properties of chromium doped Li2B4O7 glasses. The resulting O coordination shell has a contraction of the Cr-O bond lengths as compared to the Li-O bond lengths. There is also an increase in the O coordination number. (C) 2014 Elsevier B.V. All rights reserved.