Electric quadrupole and hexadecapole moment, dipole polarizability and hyperpolarizability of the copper tetramer (Cu4) from pseudopotential calculations and a comparison with all-electron ab initio results

• Published in: Computational and theoretical chemistry 2012-05, Vol.988, p.34-41
• Main Authors: Maroulis, George, Haskopoulos, Anastasios
• Format: Article
• Language: English
• Subjects: ab initio; Copper tetramer; DFT; Hyperpolarizability; Polarizability; Pseudopotentials
• ISSN: 2210-271X
• DOI: 10.1016/j.comptc.2012.02.025

[Display omitted] ► Electric properties of clusters, electric moments polarizabilities and hyperpolarizabilities. ► Pseudopotential calculations have been performed on the rhombic copper tetramer. ► Comparison to all-electron ab initio and density functional theory calculations reveal discrepancies. ► The discrepancies are of increasing importance for hyperpolarizabilities. We have obtained the electric quadrupole and hexadecapole moment, dipole polarizability and hyperpolarizability of copper tetramer from finite-field ab initio and density functional theory (DFT) calculations performed with a systematic sequence of basis sets built upon the Stevens/Basch/Krauss effective core potential triple-split basis set CEP-121G. Our present ab initio values show significant discrepancies with previous all-electron results [G. Maroulis, A. Haskopoulos, J. Comput. Theor. Nanosci. 6 (2009) 418]. Representative calculations yield self-consistent field (SCF) values (second-order Møller–Plesset results in parentheses) for (hyper)polarizability invariants: mean polarizability α¯=187.41(147.04) and anisotropy Δα=158.95 (128.09) e2a02Eh-1, mean hyperpolarizability 10-3×γ¯=551.7(123.5)e4a04Eh-3. Analogous all-electron results are α¯=196.23(161.24) and anisotropy Δα=165.71 (138.68) e2a02Eh-1, mean hyperpolarizability 10-3×γ¯=631(271)e4a04Eh-3.