Accession Number : ADA308102

Title :   Quantum Mechanical Investigation of Polymeric Properties Using a Combination of First Principle Quantum Chemical and Solid State Physical Methods.

Descriptive Note : Final rept. 1 Jun 92-30 Sep 95,

Corporate Author : ERLANGEN-NUERNBERG UNIV (GERMANY) INST FOR THEORETICAL CHEMISTRY

Personal Author(s) : Ladik, Janos

PDF Url : ADA308102

Report Date : 30 SEP 1995

Pagination or Media Count : 23

Abstract : In the HF and correlation corrected energy band structure program packages in the last year we have introduced: (1) A better localization procedure for the Wannier functions (WF) used as intermediate step in the integral transformation. (2) By changing the order of loops the integrals belonging to a certain WF group are kept in the core memory during the transformation. In this way, the amount of I/O during the calculation was reduced in a great extent. (3) The number of subroutine calls was simplified strongly by the so called inlining procedure of the subroutine calls. (4) The number of two electron integrals have been further reduced, keeping only the really non-redundant integrals which are larger than a certain threshold. (5) Finally it was made possible to stop and restart the programs at any requested time. The improved program packages were applied to calculate the correlation corrected band structures of poly(peri-naphtalene) (10 non-H atoms in the unit cell) and for nucleotide base stacks (8-11 non-H atoms in the unit cell).

Descriptors :   *QUANTUM CHEMISTRY, *MOLECULAR STRUCTURE, POLYMERS, INTEGRALS, COMPUTER PROGRAMMING, TRANSFORMATIONS(MATHEMATICS), SUBROUTINES, LOOPS, STACKING, MOLECULAR ENERGY LEVELS, NUCLEOTIDES, CORE STORAGE.

Subject Categories : Physical Chemistry
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE