Baozheng Zhang

Time-dependent DFT study on the electronic states of BBr

Abstract Using time-dependent density functional theory (TDDFT), the vertical excitation energies of BBr molecule are calculated, and the RPBE functional which has the optimum results is selected to compute the potential energy curves of the ground, the 12 valence and the 4 Rydberg excited states of BBr. The equilibrium bond distances, the vibrational frequencies and the excitation energies of nine bound states are obtained. In order to improve the theoretical results, the spin–orbital coupling effects are computed for the ground and the first excited states. Finally, the transition properties are predicted.

Ab initio study on the ground and low-lying excited states of GaH

A multireference configuration interaction (MRCI) study has been carried out on GaH. Potential energy curves and spectroscopic constants of the X 1 R þþ ,a 3 P0� ;0þ;1;2 ,A 1 P1 and a Rydberg state of 1 R þ (II) are obtained. The observed open-structure absorption bands of GaH in the region 41 650–46 300 cm � 1 can be ascribed to the transitions from this Rydberg state at about 45 000 cm � 1 to the ground state. Breit–Pauli operator is used for spin–orbit coupling effect calculations. Four X components of the bound a 3 P0� ;0þ;1;2 state are calculated for the first time. The transition properties of the excited states, including the transition dipole moments, the radiative lifetimes and the Franck–Condon factors, are predicted. 2003 Elsevier Science B.V. All rights reserved.

DFT study on the ground and the first excited states of gallium monohalides

The spectroscopic constants (SCs) of the ground states and the first excited states of gallium monohalide diatomic molecules are carried out, by using the density functional theory (DFT) with different local density approximation (LDA) and general gradient approximations (GGA), for the first time. The results obtained by different LDAs and GGAs are compared with the observed values and the theoretical results; and also compared to the results calculated with and without a combined scalar and zero order regular approximation (ZORA) relativistic corrections, respectively, showing that DFT with appropriate LDAs and GGAs are fairly successful for dealing with the ground and first excited states of these molecules with heavy elements. Furthermore, the scalar and ZORA relativistic correction are suggested as good approximate approaches.

Ab initio calculations on the ground and low-lying excited states of InCl

All-electron relativistic calculations have been performed on the low-lying electronic states of InCl by using the internally contracted multireference singles and doubles configuration interaction with the Davidson correction method. The potential energy curves and the spectroscopic constants are obtained. The C 1Π1 state has also been studied by using other internally contracted multireference methods, and it is found that the spectroscopic constants can be well reproduced by the multireference average quadratic coupled cluster method. Moreover, the essentials that affect the spectroscopic properties of the C 1Π1 state are discussed. Besides the X 1Σ+, 3Π0−, A 3Π0+, B 3Π1, 3Π2, and C 1Π1 states, some valence excited states with shallow minima close to each other and four Rydberg states are also obtained. With the aid of the theoretical results, some experimental weak bands are reanalyzed: it is proved that the so-called “D state” is not a single state in fact, but a set of closely spaced states with sha...

Ground and valence excited states of BI: A MR-CISD+Q study

Ab initio calculations on the valence electronic states of the BI molecule have been performed by using the entirely uncontracted all-electronic aug-cc-pVQZ (for the B atom) and Sadlej-pVTZ (for the I atom) basis sets and the internally contracted multireference singles and doubles configuration interaction method with Davidson size-extensively correction and Douglas-Kroll scalar relativistic correction. The potential energy curves of all valence states and the spectroscopic constants of bound states are fitted. It is the first time that the 12 Lambda-S states of BI molecule and all of the 23 Omega states generated from the former are studied in a theoretical way. Calculation results reproduce well most of the experimental data. The effects of the spin-orbit coupling and the avoided crossing rule between Omega states of the same symmetry are analyzed. The transition properties of the A3Pi0+, B3Pi1, and C1Pi1 states to the ground-state transitions are predicted, including the transition dipole moments, the Franck-Condon factors, and the radiative lifetimes. The radiative lifetime of the C1Pi1 state of BI molecule is less than 1 micros, while that of the A3Pi0+ and B3Pi1 states are the order of 1 ms.

Theoretical study of C1Π–X1Σ+ transition of InCl

Abstract Using coupled-cluster with single and double substitutions (CCSD) and based on the density functional theory (DFT), geometry optimization calculations have been performed for the ground state of InCl, and the spectroscopic constants are obtained. The potential energy curve, the spectroscopic constants and the radiative lifetimes for the vibrational levels of the C 1 Π state are also computed by the use of CCSD, the results being in accordance with the experimental values, and showing that the C 1 Π system is a quasi-bound state with a shallow well. Considering the effects of avoided crossing and barrier penetration, the maximal vibrational quantum number of the C 1 Π state should not be more than 4.

An ab initio study of the ground and valence excited states of GaF

Ab initio calculations on the ground and valence excited states of the GaF molecule have been performed by using the internally contracted multireference electronic correlation methods (MR-CISD, MR-CISD + Q, and MR-AQCC) with entirely uncontracted all-electronic basis sets and Douglas-Kroll scalar relativistic correction. The potential energy curves of all valence states and the spectroscopic constants of bound states are fitted. It is the first time that the 12 valence Lambda-S states of GaF molecule and all of the 23 Omega states generated from the former are studied in a theoretical way. Calculation results well reproduce most of the experimental data. The effects of the size-extensivity correction and the avoided crossing rule between Omega states of the same symmetry are analyzed. The transition properties of the A 3Pi0+, B 3Pi1, C 1Pi1, and 3Sigma1+ states are predicted, including the transition dipole moments, the Franck-Condon factors and the radiative lifetimes. The radiative lifetime of the C 1Pi1 state of GaF molecule is of the order of nanosecond, implying that it is a rather short-live state. The lifetimes of the B 3Pi1 and 3Sigma1+ states are of the order of microsecond, while the lifetime of the A 3Pi0+ state are the order of millisecond.

Ab initio calculations on the ground and low-lying excited states of InH

Using multiconfiguration quasi-degenerate perturbation theory (MCQDPT), the ground and the low-lying excited states of InH are studied, and the potential energy curves and the spectroscopic constants of the , a 3Π0−,0+,1,2 and A 1Π1 states are obtained. By comparing the result of all-electron basis sets with that of relativistic effective core potential (RECP) basis sets, it is found that the former is better than the latter, especially in describing the A 1Π1 state. The transition properties of the excited states, including the transition dipole moments, the radiative lifetimes and the Franck–Condon factors, are predicted. It is shown that a 3Π0+ and a 3Π1 are long-lived states, while A 1Π1 is a short-lived state.

Experimental and theoretical study on the electronic states and spectra of InBr

The dispersed laser induced fluorescence (LIF) spectra of InBr molecule are studied, the bands of the A3Π0+–X1Σ+, B3Π1–X1Σ+ and C1Π–X1Σ+ systems are observed and analyzed, and the spectroscopic constants of the C1Π state are obtained. The results indicates there are some new bound electronic states lying at about 37705 cm−1. Theoretical calculations have also been performed on the electronic states of InBr by using coupled-cluster single- and double-linear response theory (CCSD-LRT). The theoretical results agree with our experimental analyses very well.

Time-dependent density functional theory study of the electronic states of BI

By using time-dependent density functional theory, the vertical excitation energies of the boron monoiodide molecule are calculated. The Vosko–Wilk–Nusair functional with Stoll correction is used as the local density approximation, while the RPBE functional is used as the general gradient approximation for the calculations of vertical excitation energies. The potential energy curves of the ground state, the 12 valence states and the eight Rydberg excited states are plotted. The spectroscopic constants, including the equilibrium internuclear distance, re, the harmonic vibrational wavenumber, ωe, and the relative electronic energy referred to the ground state, Te, of bound states, are obtained theoretically for the first time. The transition properties of the 1 Π–X 1Σ+ transition, including the transition dipole moments, the radiative lifetimes and the Franck–Condon factors, are predicted.