Model beryllium-bonded complexes of oxirane and BeX2 (X = H, Cl) were optimized at MP2/6-311++G(d,p). The strength of the O center dot center dot center dot Be interaction was modified by sequentially replacing the protons of oxirane by F atoms. Systematic variation of the O center dot center dot center dot Be distance, Be-X bond lengths and stretching frequencies was observed. However, the most interesting trend was for the distortion of the X-Be-X angle, which is strongly dependent on the binding strength - the stronger the beryllium bond, the greater the deviation of this angle from linearity. The charge redistribution due to complexation was also investigated. (C) 2015 Elsevier B.V. All rights reserved.