Calculation of excitation energies within time-dependent density functional theory using auxiliary basis set expansions

1997 ◽  
Vol 264 (6) ◽  
pp. 573-578 ◽  
Author(s):  
Rüdiger Bauernschmitt ◽  
Marco Häser ◽  
Oliver Treutler ◽  
Reinhart Ahlrichs
2019 ◽  
Author(s):  
Kamal Batra ◽  
Stefan Zahn ◽  
Thomas Heine

<p>We thoroughly benchmark time-dependent density- functional theory for the predictive calculation of UV/Vis spectra of porphyrin derivatives. With the aim to provide an approach that is computationally feasible for large-scale applications such as biological systems or molecular framework materials, albeit performing with high accuracy for the Q-bands, we compare the results given by various computational protocols, including basis sets, density-functionals (including gradient corrected local functionals, hybrids, double hybrids and range-separated functionals), and various variants of time-dependent density-functional theory, including the simplified Tamm-Dancoff approximation. An excellent choice for these calculations is the range-separated functional CAM-B3LYP in combination with the simplified Tamm-Dancoff approximation and a basis set of double-ζ quality def2-SVP (mean absolute error [MAE] of ~0.05 eV). This is not surpassed by more expensive approaches, not even by double hybrid functionals, and solely systematic excitation energy scaling slightly improves the results (MAE ~0.04 eV). </p>


1999 ◽  
Vol 579 ◽  
Author(s):  
Naoto Uimezawa ◽  
Susumu Saito

ABSTRACTWe study tile optical absorption spectra of Na clusters using the time-dependent density-functional theory with gradient correction. A jellium-sphere background model, which is free from basis-set incompleteness error and is suitable for the comparison of various theoretical methods, is adopted. For energies of surface-plasinon excitations governing profiles of photoabsorption spectra with huge oscillator strengths., the gradient correction by van Leeiiwen and Baerends with correct asymptotic behavior of the effective potential is found to show considerable improvement over the time-dependent local-density approximation.


2005 ◽  
Vol 04 (01) ◽  
pp. 265-280 ◽  
Author(s):  
SUSUMU YANAGISAWA ◽  
TAKAO TSUNEDA ◽  
KIMIHIKO HIRAO

We investigated the electron configurations that are dominant in excited states of molecules in time-dependent density functional theory (TDDFT). By taking advantage of the discussion on off-diagonal elements in the TDDFT response matrix (Appel et al., Phys Rev Lett, 90, 043005, 2003), we can pick up electron transitions that contribute to an excitation of interest by making use of the diagonal elements of the TDDFT matrix. We can obtain approximate excitation energies by calculating a TDDFT submatrix, which is contracted for a list of collected transitions. This contracted TDDFT was applied to the calculation of excitation energies of the CO molecule adsorbing Pt 10 cluster and some prototype small molecules. Calculated results showed that a TDDFT excitation energy is dominated by a few electron configurations, unless severe degeneracy is involved.


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