Extracting double minima excited state potentials from bound–continuum spectroscopic data

Abstract

We present an extension to the bound–continuum case of our bound–bound inversion scheme for extracting excited state potentials and transition-dipoles from fluorescence data [J. Phys. Chem. Lett. 1 (2010) 3172–3176]. The procedure involves the discretization of the continuous spectrum using box-normalization. The addition of the continuous spectrum guarantees completeness of the basis set used for the implicit expansion of the unknown excited state vibrational wave functions. The method, which is found to be robust with respect to missing data or uncertainties in the line strengths, is also capable of inverting polyatomic fluorescence data. We prove the viability of the method by successfully generating the C( 1 Π u ) state of the Na 2 molecule using a fraction of the total transitions to/from the X 1 Σ g + ground state, and by extracting the double-well 2 1 Σ u + (3s+4s) curve of Na 2, assuming no prior knowledge of its structure.