Citation
Aung, Soe (1969) Part I. Approximate HartreeFock wavefunctions oneelectron properties and electronic structure of the water molecule. Part II. Perturbationvariational calculation of the nuclear spinspin isotope coupling constant in HD. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechTHESIS:01042016113458282
Abstract
Part I
Several approximate HartreeFock SCF wavefunctions for the ground electronic state of the water molecule have been obtained using an increasing number of multicenter s, p, and d Slatertype atomic orbitals as basis sets. The predicted charge distribution has been extensively tested at each stage by calculating the electric dipole moment, molecular quadrupole moment, diamagnetic shielding, HellmannFeynman forces, and electric field gradients at both the hydrogen and the oxygen nuclei. It was found that a carefully optimized minimal basis set suffices to describe the electronic charge distribution adequately except in the vicinity of the oxygen nucleus. Our calculations indicate, for example, that the correct prediction of the field gradient at this nucleus requires a more flexible linear combination of porbitals centered on this nucleus than that in the minimal basis set. Theoretical values for the molecular octopole moment components are also reported.
Part II
The perturbationvariational theory of R. M. Pitzer for nuclear spinspin coupling constants is applied to the HD molecule. The zeroorder molecular orbital is described in terms of a single 1s Slatertype basis function centered on each nucleus. The firstorder molecular orbital is expressed in terms of these two functions plus one singular basis function each of the types e^{r}/r and e^{r} ln r centered on one of the nuclei. The new kinds of molecular integrals were evaluated to high accuracy using numerical and analytical means. The value of the HD spinspin coupling constant calculated with this nearminimal set of basis functions is J_{HD} = +96.6 cps. This represents an improvement over the previous calculated value of +120 cps obtained without using the logarithmic basis function but is still considerably off in magnitude compared with the experimental measurement of J_{HD} = +43 0 ± 0.5 cps.
Item Type:  Thesis (Dissertation (Ph.D.)) 

Subject Keywords:  Chemistry 
Degree Grantor:  California Institute of Technology 
Division:  Chemistry and Chemical Engineering 
Major Option:  Chemistry 
Thesis Availability:  Public (worldwide access) 
Research Advisor(s): 

Thesis Committee: 

Defense Date:  18 November 1968 
Record Number:  CaltechTHESIS:01042016113458282 
Persistent URL:  http://resolver.caltech.edu/CaltechTHESIS:01042016113458282 
Default Usage Policy:  No commercial reproduction, distribution, display or performance rights in this work are provided. 
ID Code:  9352 
Collection:  CaltechTHESIS 
Deposited By:  Leslie Granillo 
Deposited On:  04 Jan 2016 22:41 
Last Modified:  04 Jan 2016 22:41 
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