The molecular structure and analytical potential energy function of HCO （X^2A＇）

In this paper the equilibrium structure of HCO has been optimized by using density functional theory （DFT）/ B3P86 method and CC-PVTZ basis. It has a bent （Cs, X^2A＇） ground state structure with an angle of 124.4095 °. The vibronic frequencies and force constants have also been calculated. Based on the principles of atomic and molecular reaction statics, the possible electronic states and reasonable dissociation limits for the ground state of HCO molecule have been determined. The analytic potential energy function of HCO （X^2A＇） molecule has been derived by using the many-body expansion theory. The contour lines are constructed, which show the static properties of HCO （X^2A＇）, such as the equilibrium structure, the lowest energies, etc. The potential energy surface of HCO （X^2A＇） is reasonable and very satisfactory.

Theoretical Study on the Spectroscopic Parameters and Transition Properties of MgH Radical Including Spin-orbit Coupling

An accurate theoretical study on the MgH radical is reported by adopting the high-level relativistic MRCI＋Q method with a quintuple-zeta quality basis set. The reliable potential energy curves of the five A-S states of MgH are derived. Then the associated spectroscopic parameters are determined and found to be in good accordance with the available experimental results. The permanent dipole moments （PDMs） and the spin-orbit （SO） matrix elements of A-S states are computed. The results show that the abrupt changes of PDMs and SO matrix elements are attributed to the variations of electronic configurations at the avoided crossing point. The SOC effect leads to the five A-S states split into ten Ω states and results in the double potential well of （2）1//2 state. Finally, the transition properties from the （2）1//2, （1）3//2 and （3）1//2 states to the ground state X2∑＋1//2 transitions are obtained, including the transition dipole moments, Franck-Condon factors and radiative lifetimes.

Transition Spectrum Intensities and Absorption Coefficients of Hydride BH_(2) Free Radical Molecule

We build a partition function model by product approximation first,then put the normal temperature calculated by moment square R^(2)/_(V),which has no rotational transition,approximately as a constant and applied to high temperature,and lastly program the compiler and compute the spectral line intensities and absorption coefficients of the 001-000 band for the hydride BH_(2) free radical molecule at several temperatures.The results show that the calculated values of total partition function agree with the data obtained from Gauss calculations and the fitted values by five factorial polynomials.Such excellent agreement has made it feasible to calculate the spectral line intensities and absorption coefficients at different temperatures.From the spectral figures at different temperatures,we find that they accord with the spectrum characteristic of asymmetric top molecules in some literature.This analysis has significance in measuring the high-temperature spectrum intensities of radical molecules by experiment.