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The methane dication revisited
Author(s) -
Nagesha K.,
Marathe V. R.,
Mathur D.
Publication year - 1991
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.1290050105
Subject(s) - dication , chemistry , metastability , photoionization , ab initio , atomic physics , charge (physics) , symmetry (geometry) , molecular orbital , ionization , computational chemistry , molecular physics , ion , molecule , quantum mechanics , physics , geometry , mathematics , organic chemistry
All‐electron, ab initio molecular orbital calculations have been performed on electronic states of CH 4 2+using perturbative configuration interaction procedures and large sets of Gaussian basis functions with a view to attempting reconciliation between contemporary quantum‐chemical information and different sets of experimen‐tal data from charge‐stripping, threshold photoionization, and double‐charge‐transfer mass spectrometry. Metastable electronic states of CH 4 2+are predicted for D 4 h and D 2 d symmetries, with charge‐stripping experiments likely to populate spin singles of the former symmetry. Investigation of the dissociation of CH 4 2+(D 4 h ) to CH 3 +(D 3 h )+ H + along the C 2 v symmetry pathway indicates that theoretical and experimental data on metastable states of this dication are in accord only if non‐Frank‐Condon transitions are postulated.