Non-Linear Optical Effects in Molecules.
Abstract
We analyze the evolution of first principle molecular theory in obtaining reliable values of molecular hyperpolarizabilities. Such quantities place severe demands on the capability of quantum chemistry, as large basis sets, frequency dependence, and high levels of electron correlation are all shown to be essential in obtaining observed, gas phase hyperpolarizabilities to within an error of 10%. Ab initio Hartree Fock results are typically in error by nearly a factor of two, while the errors due to the neglect of frequency dependence average about 1O to 3O% depending upon the particular process. It is also shown that for small molecules, standard semiempirical approaches, like INDO and INDO/S, will often not even give the correct sign for hyperpolarizabilities. It is demonstrated that using state of the art correlated, frequency dependent methods, it is possible to provide results to within 10%. Excluding any one of the essential elements, though, destroys the agreement
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 1996
- Accession Number
- ADA306197
Entities
People
- Rodney J. Bartlett
Organizations
- University of Florida