Application of the method of continued fractions to multichannel studies on electron-impact excitation of the B-1 Sigma(+)(u), (CIIu)-I-1 and E(F)(1)Sigma(+)(g) states in H-2

In the present work, the method of continued fractions at a five-channel cl ose-coupling level of approximation is applied to study the low-energy elec tron-impact excitation in linear molecules. Particularly, cross sections fo r the X(1)Sigma (+)(g)-->B(1)Sigma (+)(u), X(1)Sigma (+)(g)-->E(F)(1)Sigma (+)(g), and X(1)Sigma (+)(g)-->(CIIu)-I-1 transitions in H-2 in the (15-40) eV energy range are reported. No orthogonality constraint between the boun d and continuum orbitals is imposed in the present study and the one-electr on exchange terms are explicitly considered. Comparison between our calcula ted cross sections with the available experimental data and other theoretic al results is made. (C) 2001 Elsevier Science B.V. All rights reserved.