The 3-D bonding morphology of the infra-red active normal modes of benzene

Highlights: • Present a new vector-based interpretation of the chemical bond B{p,q,r} for benzene. • Provide a 3-D bonding morphology of the infra-red (IR) active normal modes of benzene. • Show variation of the bond-path framework set B{p,q,r} with frequency. • Comprises the least (p-), most preferred (q-) directions of ρ(r_b) and the bond-path (r). • Show cooperative effects of the CH and CC bonds of the four IR active modes of benzene. We present for the first time a visualization of the 3-D morphology of all the CC and CH bonds for the relaxed structures as well as four infra-red (IR) active normal modes of benzene using the complete bond-path framework set B = {p,q,r} a vector-based interpretation of the chemical bond within the QTAIM framework. The bond-path framework set B = {p,q,r} comprises three strands in the ground state, with the r-path corresponding to the familiar QTAIM bond-path. The new p- and q-paths are formulated from the least and most preferred directions of electron density accumulation respectively.