S.L. Moors, S. Michielssens, C. Flors, P. Dedecker, J. Hofkens, A. Ceulemans Journal of Chemical Theory and Computation (JCTC) 4 (6), 1012-10202008A1Published while none of the authors were employed at the CMMDOI http://dx.doi.org/10.1021/ct8000359