Analysis of vibrational modes of the P4 molecule through hyperspherical variants of the local orthogonal coordinates: the limit of dissociation in dimers

Abstract

In this work, we discuss the representation in different orthogonal coordinates sets of highly symmetric P4 molecule whose equilibrium configuration is tetrahedral. For this purpose, the H (or diatom–diatom) and Wigner orthogonal representations are used to study the singlet (ground) electronic state of the title molecule, whereas the V (or diatom–satellites) scheme is used in the triplet electronic state analysis. The equilibrium geometries and the respective electronic energies of Pn, n = 1,…,4, are determined using the coupled cluster and DFT methodologies. Moreover, the vibrational harmonic modes and the minimum energy path of the P4 dissociation in P2 dimers are calculated within DFT procedure. From these calculations, the diatom–diatom and Wigner vectors are used to analyze the behavior of vibrational modes, and the possible fragmentation channels (P4 → 2P2, P3 + P, P2 + 2P, 4P) are discussed. The presented results are compared, when available, with previous theoretical and experimental ones.