Globally Accurate Potential Energy Surface for BH2(1A') Using the Switching Function Formalism.

A great number of energy points are calculated using the aug-cc-pV(,5)Z basis sets at the multireference configuration interaction level and extrapolated to the complete basis set limit. An exact three-dimensional potential energy surface of the ground-state BH is obtained. A switching function is developed to model the transition of B(P) to B(S) to guarantee the reliable behavior at B(P) + H(∑) and BH(∑) + H(S) dissociation limits. The various topographic features of the new global potential energy surface are discussed in detail, showing a good agreement with the previous results from the theory. The quasi-classical trajectory method is utilized to calculate the integral cross sections of the B(P) + H(∑) ( = 0, = 0) → BH(∑) + H(S) reaction, which can provide another support for reliability of the title potential energy surface.