Rotation spectrum and infrared fundamental bands of¹²³SbD₃. Determination of molecular geometry andab initiocalculations of spectroscopic parameters

A theoretical-spectroscopy, ab initio-based study of the electronic ground state of 121SbH3

“…In the present paper, we extend our previous work on stibine SbH 3 [15], in particular by computing values for the electric dipole transition moments based on a new ab initio DMS and on a 'spectroscopic' PES that is determined by least-squares fitting to available experimentally derived vibrational energies, using an ab initio PES [15,26,27] as starting point. To calculate the ab initio DMS we used the CCSD(T) method in conjunction with the pseudopotential ECP46MWB [28] and the SDB-aug-cc-pVTZ basis [29] to describe the Sb atom and the aug-cc-pVTZ basis set [30] to describe the hydrogen atoms.…”

“…Liu et al [44] reported an ab initio three-dimensional Sb-H stretching DMS of SbH 3 together with band intensities for stretching bands below 11000 cm −1 . Even the most recent ab initio PESs of stibine computed at state-of-the-art level of theory [27] are not sufficiently accurate for spectroscopic applications. This situation is usually resolved by adjusting the PES empirically in fits to experimental data.…”

“…Halonen et al [35] reported relative band intensities for stretching vibrational bands with up to four stretching quanta excited. Recently, the high-resolution infrared spectrum of 121 SbD 3 was recorded and various fundamental levels were characterized by Canè et al [27].…”

“…Another local mode analysis of the vibrational energies of stibine was carried out by means of the creation and annihilation operators technique [41,42]. Ab initio studies [26,27] were performed to calculate the PES, the dipole moments, the equilibrium geometries, and effective rotation-vibration constants for 121 SbH 3 and 123 SbH 3 , and 123 SbD 3 . Pluchart et al [43] used their algebraic approach to describe vibrational modes of SbH 3 .…”

“…We start from an ab initio PES of stibine [27] and refine it by fitting to the available experimental band centers. We also compute a new six-dimensional ab initio DMS of SbH 3 , which is utilized for simulating the absorption spectrum at an absolute temperature of T = 300 K.…”