Ren Ting-Qi

Potential energy curves and analytical potential energy functions of the metastable states of B2

The multi-reference configuration interaction method and aug-cc-pvqz (AVQZ) have been used to calculate potential energy curves (PECs) of the singlet and triplet states of the ∏u and ∏g symmetry of B2++. All of the four states (1∏u, 1∏g, 3∏u and 3∏g) are found to be metastable states, though the potential well of 3∏u symmetry is very shallow. Based on the PECs, the analytical potential energy functions (APEFs) of these states have been fitted using the least square fitting method and two models of function. The spectroscopic parameters of each state are also calculated, and are compared with other investigations in the literature. The credibility and veracity of the two functions are evaluated. Some ideas to improve the fitting accuracy are presented. Also the vibrational levels for each state are predicted by solving the Schrodinger equation of nuclear motion.

Electronic structure of one-dimensional boron chains with density functional theory method

One-dimensional chain structures of Bn (n = 6-16) are calculated by employing a 6-311G* basis set. The present calculations show that all the chain structures of interest have local minima with large binding energy per atom and short bond length. It is also found that many previous reported structures of B6 and B7 clusters are saddle points and the one-dimensional chain structures are the corresponding ground-state structures of B6 and B7 clusters.

Analytic Expression of Arbitrary Matrix Elements for Boson Exponential Quadratic Polynomial Operators

Making use of the transformation relation among usual, normal, and antinormal ordering for the multimode boson exponential quadratic polynomial operators (BEQPOs), we present the analytic expression of arbitrary matrix elements for BEQPOs. As a preliminary application, we obtain the exact expressions of partition function about the boson quadratic polynomial system, matrix elements in particle-number, coordinate, and momentum representation, and P representation for the BEQPOs.

Molecular Dynamics Study of Gases H2, D2 and T2*

The classical molecular dynamics simulation has been used to study the equation of state of gas H2, D2 and T2. It has also been investigated that the isotope mass affects on the accuracy of equation of state. Our calculated results show that the classical effect is principal and the isotope mass effects on the equation of state are obvious for the much light gases. At the same time, some useful theoretical data of equation of state for these gases have been provided. It is found that the classical simulation is still effective to the quantum gas. However, the quantum mechanics simulation and the improvement of intermolecular interaction potential are necessary if more accurate computational results are expected.

Accurate quantum chemical calculation of cross sections for the system D+H2 DH+H

Accurate reactive scattering calculations of reactive probabilities and integral cross sections for the system D+H2 → DH+H were carried out by using the quantum mechanical time-dependent wave packet methods. In order to simplify the calculation, we introduced the centrifugal sudden approximation to reduce the effective degrees of freedom, and show results of new calculations. In particular, the present calculations were extended to all angular momentum and obtained reaction cross sections for a range of energies. The results were also compared with those of other theoretical calculations and the differences were discussed.

DISTORTED WAVE-WAVE PACKET APPROACH TO VIBRATIONAL DEACTIVATION OF DIATOMIC MOLECULE BY COLLISIONS WITH SOLID SURFACE

A model is proposed for vibrational dexcitation of diatomic molecule by collisions with a solid surface, and used to predict the rotational and translational energy distributions and other properties of interest. It is found that molecular rotation dominates over translation in receiving the vibrational energy released, even for the heavier diatomic molecules.

DISTORTED WAVE CORRECTION OF CENTRIFUGAL SUDDEN WAVE PACKET APPROXIMATION

A distorted wave procedure is employed to correct the centrifugal sudden wave packet approximation, and the accurate results compared with the standard close coupling method for m-dependent integral cross sections for short- and long- range Ar+N2 potentials at E = 0.0258 eV are obtained only by using the second-order corrections to the CSWP wave function.