Calculation of electric dipole (hyper)polarizabilities by long-range-correction scheme in density functional theory: a systematic assessment for polydiacetylene and polybutatriene oligomers.

Abstract

Using the long-range correction (LC) scheme combined with the BLYP exchange-correlation functional within density functional theory, (hyper)polarizabilities were computed for polydiacetylene and polybutatriene oligomers. Benchmarking against coupled-cluster calculations at the CCSD(T) level revealed that the well-known overestimation produced by conventional functionals is reduced but not fully corrected by the LC approach. Furthermore, no definitive advantage of LC-BLYP over Hartree-Fock results was identified. These findings align with prior work on polyacetylene and molecular hydrogen oligomers, providing a comprehensive characterization of LC-BLYP performance for quasi-linear conjugated systems.