UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Study of the BH molecule Gagnon, Paul Joseph

Abstract

Antisymmetrized geminal product wavefunctions with several limited basis sets were calculated for the ground state of BH at R=2.329 atomic units. Extending these wavefunctions to include Kapuy's "one-electron transfer" configurations resulted in a lowering in energy of ~0.01 atomic units. In our case, this improvement accounts for more than 90% of that achieved by a full configuration-interaction wavefunction. A "contracted" double-zeta basis set yielded the best overall energy. A 13-term, "split core", configuration-interaction wavefunction was developed and yielded an energy of -25.14769 atomic units. This wavefunction was then made to satisfy the virial theorem. Parr and White's method for one-point force constant calculation was applied to the scaled wavefunction with negative results. A similar wavefunction was partially optimized at three internuclear distances followed by scaling with fixed R.Various parabolic models were used to fit the virial forces and energies corresponding to each R value. The force constants k(e) calculated from these models were usually very good and the effect of scaling was shown to be important. Parabolic expansions in 1/R gave better results than parabolas in R, compared to a quintic model and to experimental values.

Item Media

Item Citations and Data

License

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

Usage Statistics