Comprehending the quadruple bonding conundrum in C₂ from excited state potential energy curves.

ABSTRACT: The question of quadruple bonding in C₂ has emerged as a hot button issue, with opinions sharply divided between the practitioners of Valence Bond (VB) and Molecular Orbital (MO) theory. Here, we have systematically studied the Potential Energy Curves (PECs) of low lying high spin sigma states of C₂, N₂, Be₂ and HC[triple bond, length as m-dash]CH using several MO based techniques such as CASSCF, RASSCF and MRCI. The analyses of the PECs for the ^2S+1Σ_g/u (with 2S + 1 = 1, 3, 5, 7, 9) states of C₂ and comparisons with those of relevant dimers and the respective wavefunctions were conducted. We contend that unlike in the case of N₂ and HC[triple bond, length as m-dash]CH, the presence of a d

SUBMITTER: Bhattacharjee I 

PROVIDER: S-EPMC7499457 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature