An ab initio study of the vibronic, spin–orbit and hyperfine coupling in the X2Π electronic state of the CCCD radical

An ab initio study of the vibronic, spin-orbit, and magnetic hyperfine structure in the X2Pi electronic state of NCO

In the present study we give the results of the ab initio calculations on the vibronic, spin-orbit, and magnetic hyperfine structure in the X (2)Pi electronic state of the NCO radical. The calculations of the potential surfaces and the electronic mean values of the hyperfine coupling constants are carried out by means of the density functional theory approach (B3LYP functional combined with an atomic orbital basis set suitable for calculations of the hyperfine structure). The vibronic levels, spin-orbit splitting, and the vibronic mean values of the components of the hyperfine tensor in the vibronic species are calculated using a variational method. The results of the calculations are in good agreement with the available experimental data.

Theoretical investigation of the hyperfine structure in spatially and spin degenerate electronic states of triatomic and tetra-atomic molecules

The present paper reviews the results of ab initio studies on the magnetic hyperfine structure in spectra of spatially and spin degenerate electronic states of triatomic and tetra-atomic molecules. The main goal of the present paper is to show that such theoretical investigations can be used to reliably reproduce, explain and predict the results of the corresponding measurements.

An ab initio calculation of the anisotropic hyperfine coupling constants in the low-lying vibronic levels of the X [sup 2]Π electronic state of CCCH

The results of ab initio calculations of the vibronically averaged components of the anisotropic magnetic hyperfine tensor in the low-lying vibronic species of the X (2)Pi electronic state of CCCH and CCCD are reported. The electronically averaged hyperfine coupling constants for hydrogen and (13)C in (12)C (12)C (12)CH, (13)C (12)C (12)CH, (12)C (13)C (12)CH, (12)C (12)C (13)CH, and (12)C (12)C (12)CD are obtained as functions of two bending vibrational modes by the density functional theory method. The vibronic wave functions are calculated with help of a variational approach which takes into account the Renner-Teller effect and spin-orbit coupling. The results of the present study help to reliably interpret the experimental data previously published and predict the yet unobserved hyperfine structure in excited vibronic states of CCCH and CCCD.