The Effective Potential Energy Surfaces of the Nonadiabatic Collision B(²P_ja) + H₂(¹Σ⁺_g,ν,j) ↔ B(²P_j'a) + H₂(¹Σ⁺_g,ν',j')

Author

Matthew B. Garvin

Date of Award

3-9-2009

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Engineering Physics

First Advisor

David E. Weeks, PhD

Abstract

Effective potential energy surfaces (PESs) are calculated for a nonadiabatic collision . This calculation employed 1 ²A', 2 ²A' and 1 ²A" adiabatic PESs numerically calculated at the state-averaged multiconfigurational self-consistent field (SA-MCSCF)/configuration interaction (CI) level for several values of the H₂ bond length, H₂ orientation angle, and boron distance. The associated nonadiabatic coupling terms (NACTs) were calculated from the SA-MCSCF/CI wave functions using analytic gradient techniques. A line integral through the NACTs was then used to determine the adiabatic-to-diabatic mixing angle required to transform from the 1 ²A' and 2 ²A' adiabatic basis to a corresponding diabatic basis. When all nonadiabatic coupling terms between all electronic states are considered, the line integral is path independent. However, only NACTs between the 1 ²A' and 2 ²A' states were considered in these calculations, and the line integral was therefore path dependent. The path dependence of the line integral was used to characterize the error introduced by employing a truncated set of adiabatic states. A method for reducing the effect of this error through the use of symmetry derived boundary conditions was developed. The resulting diabatic PESs were combined with the total B + H₂ rotational kinetic energy and boron spin-orbit coupling to yield diabatic effective PESs. The diabatic effective PESs were diagonalized to yield adiabatic effective PESs. Diabatic effective PESs data was extracted for the equilibrium H₂ bond length and used to calculate inelastic scattering matrix elements using the time dependent channel packet method.

AFIT Designator

AFIT-DS-ENP-09-J01

DTIC Accession Number

ADA494623

Recommended Citation

Garvin, Matthew B., "The Effective Potential Energy Surfaces of the Nonadiabatic Collision B(²P_ja) + H₂(¹Σ⁺_g,ν,j) ↔ B(²P_j'a) + H₂(¹Σ⁺_g,ν',j')" (2009). Theses and Dissertations. 2434.
https://scholar.afit.edu/etd/2434