Beyond Born–Oppenheimer based diabatic surfaces of 1,3,5-C6H3F3+ to generate the photoelectron spectra using time-dependent discrete variable representation approach

• Published in: Physical chemistry chemical physics : PCCP Vol. 24; no. 4; pp. 2185 - 2202
• Main Authors: Mukherjee, Soumya, Satyam Ravi, Dutta, Joy, Sardar, Subhankar, Adhikari, Satrajit
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 26.01.2022
• Subjects: Adiabatic flow; Couplings; Electron states; Formulas (mathematics); Hilbert space; Mathematical analysis; Photoelectrons; Potential energy; Representations; Spectra; Time dependence
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/d1cp04733g

In this article, Beyond Born–Oppenheimer (BBO) treatment is implemented to construct diabatic potential energy surfaces (PESs) of 1,3,5-C6H3F3+ over a series [eighteen (18)] of two-dimensional (2D) nuclear planes constituted with eleven normal modes (Q2, Q9x, Q9y, Q13x, Q13y, Q18x, Q18y, Q10x, Q10y, Q12x and Q12y) to include all possible nonadiabatic interactions among six coupled electronic states (X2E′′, [Formula Omitted], B2E′ and [Formula Omitted]). We had formulated explicit expressions of adiabatic to diabatic transformation (ADT) equations [S. Mukherjee, J. Dutta, B. Mukherjee, S. Sardar and S. Adhikari, J. Chem. Phys., 2019, 150, 064308] for the same system forming six state sub-Hilbert space and at present, these ADT equations are solved by incorporating MRCI level ab initio adiabatic PESs and CP-MCSCF calculated nonadiabatic coupling terms (NACTs) to derive diabatic PESs and couplings. Such single-valued, smooth, symmetric and continuous diabatic surface matrices are utilized to carry out multi-state multi-mode nuclear dynamics with the help of time-dependent discrete variable representation (TDDVR) methodology to compute the photoelectron (PE) spectra of 1,3,5-C6H3F3. Our theoretically calculated spectra for X2E′′, [Formula Omitted] and [Formula Omitted] states using BBO treatment and TDDVR dynamics show peak by peak correspondence with the experimental results as well as better than the findings of the multi-configuration time-dependent Hartree (MCTDH) method.