Spectroscopic constants and potential energy curves of GaBr

The Ground and Valence Excited States of GaBr: A MR-CISD+Q Study

“…With the development of ab initio methods and computer technology, some calculations on the electronic state structures of GaBr have been reported in recent years. − However, most of these theoretical studies focused on the ground state, and none of these previous calculations had included the effect of spin−orbit coupling (SOC). It's well known that the SOC plays an important role in the spectroscopy and dynamics of molecules, even in the light molecules that contain only atoms of the first row of the periodic table.…”

High-Level Theoretical Study of the C1Π States of GaCl, GaBr, InCl, and InBr

“…The gallium and indium monohalides (MX, M = Ga or In and X = halogen) play important roles in the development of new semiconductor devices and optoelectronic materials due to their unique physical and chemical properties. , There have been plenty of experimental and theoretical studies on the spectra and low-lying electronic states of these gaseous molecules − (see also the literature collected in refs , , , and ), which deepen the understanding of their electronic structures. There are totally 10 valence electrons in these molecules as in the case of N 2 , leading to fairly high excitation energies between the ground and excited states with the absorption wavelengths in the near-ultraviolet region.…”

“…In addition to the valence states with the asymptote M­( 2 P) + X­( 2 P), there is also an excited state 1 Σ + which dissociates into the limit M + ( 1 S) + X – ( 1 S) but was neglected in most theoretical calculations. Rydberg states. Theoretical calculations show that these states dissociate into the asymptotes related to the Rydberg levels of M, that is, ns 2 (n+1)­s 1 2 S, ns 2 (n+1)­p 1 2 P, and so on. − ,,, Some Rydberg states of GaCl and InCl have also been detected at above 50 000 cm –1 in energy by resonance-enhanced multiphoton ionization (REMPI). , Moreover, for GaCl, GaBr, InCl, and InBr, some continuum emission spectra observed in the green and blue regions were assigned to the transitions from Rydberg states to C 1 Π − and had been confirmed by theoretical calculations. , Ionized states. Above 70 000 cm –1 there are ionized states due to MX + with the ground one X 2 Σ + (or A 2 Π in the dissociation region). ,, In addition, some band systems of InCl in early studies were finally reassigned as the ones of InCl + (cf.…”

“…Rydberg states. Theoretical calculations show that these states dissociate into the asymptotes related to the Rydberg levels of M, that is, ns 2 (n+1)­s 1 2 S, ns 2 (n+1)­p 1 2 P, and so on. − ,,, Some Rydberg states of GaCl and InCl have also been detected at above 50 000 cm –1 in energy by resonance-enhanced multiphoton ionization (REMPI). , Moreover, for GaCl, GaBr, InCl, and InBr, some continuum emission spectra observed in the green and blue regions were assigned to the transitions from Rydberg states to C 1 Π − and had been confirmed by theoretical calculations. , …”

“…On the theory side, although many high-precision quantum chemistry methods have been well-developed and are applicable to the diatomic molecules of main group elements, the computed depth of the potential well of C 1 Π often varies wildly for a given MX molecule, − and the agreement of spectroscopic constants with the experimental ones is not satisfactory as well. In Section One of the Supporting Information, for example, PECs of the C 1 Π state of InCl have been computed by different multiconfigurational methods, including the complete active space self-consistent field (CASSCF) , with an active space of eight valence electrons in seven valence orbitals (8e,7o), a series of traditional multireference methods, the density matrix renormalization group (DMRG) method , with the active space (8e,25o), and DMRG-CASPT2.…”