A main purpose of this Letter is to show how to employ the inverse Born-Oppenheimer approximation as a basis set to study zero kinetic energy (ZEKE) spectroscopy and the autoionization dynamics of the ZEKE states. The calculations of channel couplings, quantum defects, intensity borrowing, vibrational and rotational autotionizations will be demonstrated by using a homonuclear diatomic molecule as an example. (C) 2010 Elsevier B. V. All rights reserved.