Performance of the elongation method with larger basis sets

The elongation method proposed by Imamura serves as a theoretical model for polymerization processes. It can now be used together with larger basis sets, Hartree-Fock and density functional methods from the Gaussian 94 package with direct self-consistent field (SCF). This allows electronic structure calculation of elongating clusters with an efficiency superior to full cluster calculations and a precision superior to previous versions of our elongation method. Performance and accuracy compared with full cluster calculations on a regular polymer using the BLYP/6-31G(d, p) method. Interaction energies of water and hydrogen fluoride polymers of increasing length are compared between HF, BLYP methods and 4-31G, 6-31G(d, p) basis sets: Diffuse and polarization functions have a large influence on the interaction energy on both polymers. Local density of states are calculated for different cluster lengths. They are in good agreement with full cluster calculations.