
Accession Number : ADA241079
Title : Direct AtomicOrbital Based TDHF Calculations of FrequencyDependent Polarizabilities.
Descriptive Note : Technical rept.,
Corporate Author : UTAH UNIV SALT LAKE CITY DEPT OF CHEMISTRY
Personal Author(s) : Feyereisen, Martin ; Nichols, Jeff ; Oddershede, Jens ; Simons, Jack
Report Date : 23 SEP 1991
Pagination or Media Count : 37
Abstract : We have formulated and implemented a direct atomic integral driven method for the calculation of frequency dependent response properties at the selfconsistent field (SCF) level. By avoiding the integral transformation step, as well as the storing and retrieving of atomicorbital (ao) based integrals, we are able to use large basis sets. The practicality of the approach is illustrated and calibrated by performing a series of calculations on cyclopropenone employing up to 232 basis orbitals. We examined the scaling of the dipole polarizability with the site of the system for paranitroaniline and its dimer. Except for a small positive enhancement of the component along the molecular axis, we find little effect of size on alpha for the system. However, if the NN linkage of the dimer is replaced by a CC linkage, thus more effectively extending the orbital conjugation by making the dimer planar, we find a large, frequencydependent increase in the polarizability relative to twice that of the monomer (factors varying from 3 to 18, depending on frequency).
Descriptors : COMPUTATIONS, CONSISTENCY, DIMERS, DIPOLES, FREQUENCY, INTEGRALS, LINKAGES, MOLECULES, OPTIMIZATION, POLARIZATION, RESPONSE, SITES, SIZES(DIMENSIONS), TRANSFORMATIONS.
Subject Categories : Atomic and Molecular Physics and Spectroscopy
Distribution Statement : APPROVED FOR PUBLIC RELEASE