SPS organises a seminar by Satrajit Adhikari

Event From Date: 
Tuesday, 22 May 2018
Event End Date: 
Tuesday, 22 May 2018
Event Title: 
SPS organises a seminar by Satrajit Adhikari
Event Details: 


School of Physical Sciences
Jawaharlal Nehru University, New Delhi


Beyond Born-Oppenheimer Theories on Spectroscopy, Scattering and Phaseansitions


Speaker: Satrajit Adhikari
(Indian Association for the Cultivation of Science, Kolkata)


Date: 22– May -2018
Time: 4 p.m, Tuesday
Venue: Seminar Room, SPS


Abstract : Beyond Born-Oppenheimer (BBO) theories are formulated from first principle for the construction of diabatic potential energy surfaces (PESs) both for spectroscopic [1-3] (Na3, K3, NO2, NO3, C6H6+ and C6H3F3+ ) and scattering [4] processes (D++ H2). Jahn-Teller (JT) and Renner-Teller (RT) types of conical intersections (CIs) along with Pseudo Jahn-Teller (PJT) interactions in those systems and semi-circular CI seam (rather than a CI point) between the ground and first excited states of H3 + system are the new interesting observations. Nuclear dynamics are performed on the diabatic PESs of Na3, NO2 and NO3 to calculate the photoelectron spectra, which match quite well with the experimentally measured ones. We have also carried out reactive scattering dynamics [4,5] on the diabatic surfaces for H3 + system in hyperspherical coordinates for total angular momentum zero and non-zero situation to reproduce experimental cross sections and rate coefficients for reactive non-charge and charge transfer processes.
Optical spectra of REMnO3 (RE = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy) shows anomalous temperature dependence around the Neel temperature [6]. This behavior could be due to Jahn-Teller effect both in ground and excited state. Such observations have been investigated [7] theoretically to interprete the experimental spectra due to the excitations of the quantum rotors.