Calculations of two-photon absorption cross sections by means of density-functional theory

• Published in: Chemical physics letters Vol. 374; no. 5; pp. 446 - 452
• Main Authors: Sałek, Paweł, Vahtras, Olav, Guo, Jingdong, Luo, Yi, Helgaker, Trygve, Ågren, Hans
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 18.06.2003; Elsevier Science
• Subjects: Atomic and molecular physics; Calculations and mathematical techniques in atomic and molecular physics (excluding electron correlation calculations); Coupled cluster theory; Density-functional theory; Electronic structure of atoms, molecules and their ions: theory; Exact sciences and technology; exchange; integration; molecules; Physics; state; Statistical model calculations (including Thomas-Fermi and Thomas-Fermi-Dirac models); systems; Theoretical study; Density functional method; Transition moments; Two photon absorption; Coupled cluster method; Nonlinear optics; Cross sections
• ISSN: 0009-2614; 1873-4448; 1873-4448
• DOI: 10.1016/S0009-2614(03)00681-X

We present density-functional theory and calculations for two-photon absorption spectra of molecules. The two-photon absorption cross sections are defined in terms of the single residues of the quadratic response function, which was recently derived for density-functional theory using the time-dependent variation principle and the quasi-energy ansatz. The cross-section dependence on different functionals, including the general gradient approximation and hybrid theory, is examined for a set of small molecules. The results of hybrid density-functional theory compare favorably with those from singles-and-doubles coupled-cluster response calculations.