Absorption cross-section of the C2H molecule:: proper treatment of the conical intersection

In this Letter we study the influence of proper treatment of the conical intersection on photo-absorption cross-section of the C2H molecule. The treatment is based on the diabatization of the adiabatic potentials employing the adiabatic-to-diabatic transformation. To facilitate the calculations we adopt a simple two-dimensional model. (C) 2003 Elsevier Science B.V. All rights reserved.