TY - JOUR

T1 - Ab initio mixed polarizabilities responsible for the Raman-forbidden ν 2 transition in carbon dioxide molecule

AU - Коузов, Александр Петрович

AU - Финенко, Артем Андреевич

AU - Чистиков, Даниил

PY - 2026/3/20

Y1 - 2026/3/20

N2 - The vibrational parity of a centrosymmetric molecule can be broken in the Ramanspectra when the electric-dipole (E1) virtual transitions are accompanied by theelectric-quadrupole (E2) or magnetic-dipole (M1) ones. To assess the intensity ofthe not yet detected ν2 CO2 Raman band, accurate ab initio values of the mixedE1-E2 (Aˆ) and E1-M1 (Gˆ) polarizabilities of a bent CO2 are presently obtainedusing the DALTON program suite. The previous SCF results of Amos, Buckingham and Williams (Mol. Phys. 39, 819 (1980)) for the Aˆ-tensor components aresubstantially refined by employing the extended basis sets and accounting for theelectron correlation (up to CCSD). By using the SOPPA approach, the derivativesof Gˆ are obtained for the first time. The results are processed to derive the rank-rirreducible spherical tensors (IST) Xκ(r) which vary in space as the Wigner functions Dκm (r) whose subscript κ determines the dependence on the bent-molecule planeorientation relative to the symmetry axis. As a result, four ISTs (A(1) 1 , A(2) 1 , A(3) 1and A(3)3 ) fully determine the ν2 E1-E2 intensity whereas two tensors G(1) 1 and G(2) 1do the same for the magnetic channel. Using the thus derived properties, the integrated ν2−band intensities are calculated for the first time and, like our recentassessments for the ν3 band (Opt. Spektrosk. 133, 607 (2025)), show the leadingrole of the E1-M1 terms. The results could be helpful for detection of this novelparity-changing Raman process.

AB - The vibrational parity of a centrosymmetric molecule can be broken in the Ramanspectra when the electric-dipole (E1) virtual transitions are accompanied by theelectric-quadrupole (E2) or magnetic-dipole (M1) ones. To assess the intensity ofthe not yet detected ν2 CO2 Raman band, accurate ab initio values of the mixedE1-E2 (Aˆ) and E1-M1 (Gˆ) polarizabilities of a bent CO2 are presently obtainedusing the DALTON program suite. The previous SCF results of Amos, Buckingham and Williams (Mol. Phys. 39, 819 (1980)) for the Aˆ-tensor components aresubstantially refined by employing the extended basis sets and accounting for theelectron correlation (up to CCSD). By using the SOPPA approach, the derivativesof Gˆ are obtained for the first time. The results are processed to derive the rank-rirreducible spherical tensors (IST) Xκ(r) which vary in space as the Wigner functions Dκm (r) whose subscript κ determines the dependence on the bent-molecule planeorientation relative to the symmetry axis. As a result, four ISTs (A(1) 1 , A(2) 1 , A(3) 1and A(3)3 ) fully determine the ν2 E1-E2 intensity whereas two tensors G(1) 1 and G(2) 1do the same for the magnetic channel. Using the thus derived properties, the integrated ν2−band intensities are calculated for the first time and, like our recentassessments for the ν3 band (Opt. Spektrosk. 133, 607 (2025)), show the leadingrole of the E1-M1 terms. The results could be helpful for detection of this novelparity-changing Raman process.

KW - magnetic and quadrupolar contributions to Raman scattering; ab initio mixed electronic polarizabilities; parity-changing vibrational Raman transitions

UR - https://www.mendeley.com/catalogue/9ccc05f5-cca5-3738-b520-7a239d2fc29e/

U2 - 10.1063/5.0312738

DO - 10.1063/5.0312738

M3 - Article

VL - 164

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 11

M1 - 114308

ER -