Ab initio nonadiabatic study of the 3pπ D 1Πu+ state of H2 and D2

We present nonadiabatic, fully ab initio, systematic calculations of the 3p pi D (1)Pi(+)(u) level energies, Lambda doublings, and absorption line intensities and widths for H-2 and D-2 even for those levels that are strongly predissociated. The multichannel quantum defect theory calculations are based on the latest quantum-chemical clamped-nuclei data of Wolniewicz and collaborators [L. Wolniewicz and G. Staszewska, J. Mol. Spectrosc. 220, 45 (2003); G. Staszewska and L. Wolniewicz, ibid. 212, 208 (2002)]. The theoretical values are compared with previously published data [G. D. Dickenson, T. I. Ivanov, M. Roudjane, N. de Oliveira, D. Joyeux, L. Nahon, W.-U. L. Tchang-Brillet, M. Glass-Maujean, I. Haar, A. Ehresmann, and W. Ubachs, J. Chem. Phys. 133, 144317 (2010); G. D. Dickenson, T. I. Ivanov, W. Ubachs, M. Roudjane, N. de Oliveira, D. Joyeux, L. Nahon, W.-U. L. Tchang-Brillet, M. Glass-Maujean, H. Schmoranzer, A. Knie, S. Kubler, and A. Ehresmann, Mol. Phys. 109, 2693 (2011)] and with absolute line intensity measurements. The overall agreement is very good. The enhanced precision of the calculations leads to additional assignments and to several corrections of previous literature data.