Low-lying electronic states of SiF+ specie
MRCI, spectroscopy, diatomics.
In this study, the structural, energetic and spectroscopic parameters of the low-lying electronic states (Λ + S) of the SiF+, correlating with the two lowest dissociation channels [Si+(2Pu) + F(2Pu) e Si+(4Pg) + F(2Pu)], were obtained at MRCI+Q/aug-cc-pV5Z theory level. At this level, the energy difference between these dissociation channels (41145 cm-1), corresponding to excitation Si+(2Pu) - Si+(4Pg). Of the twelve states that correlate with the first dissociation channel, eight of them are stable, (X 1Σ+, 1 3Π, 1 3Σ+, 1 3Δ, 1 1Δ, 1 1Σ-, 1 3Σ+, 2 1Σ+), while for the second channel, only five states were show to be energetically stable, (3 3Π, 1 5Π, 2 3Σ+, 4 3Π, 3 3Σ+). For the ground electronic state (X 1Σ+), the internuclear distance (Re) and vibrational frequency (𝜔e), at MRCI+Q/aug-cc -pV5Z, were 2,891 a0 and 1,043 cm-1, respectively. For the first excited state, (1 3Π), these values were 2,929 a0 and 981 cm-1, respectively. The values obtained in this study are in excellent agreement with previous theoretical and experimental studies. Based on the accurate description of these states, this work provides the structural, energetic and spectroscopic parameters for the first time in the literature, for the electronic states correlated with the second dissociation channel.