scholarly journals Modelling excited states of weakly bound complexes with density functional theory

2014 ◽  
Vol 16 (28) ◽  
pp. 14455-14462 ◽  
Author(s):  
Edward A. Briggs ◽  
Nicholas A. Besley
Keyword(s):  
Density Functional Theory ◽  
Excited States ◽  
Density Functional ◽  
Rydberg State ◽  
Dispersion Correction ◽  
Weakly Bound ◽  
Functional Theory ◽  
Weakly Bound Complexes

Different dispersion correction parameters are required to describe the interaction when the molecule is in an excited Rydberg state.

Density functional theory (DFT) calculations on the structures and stabilities of [CnO2n+1]2– and [CnO2n+1]X2 polycarbonates containing chainlike (CO2)n units (n = 2–6; X = H or Li)

2011 ◽  
Vol 89 (6) ◽  
pp. 671-687 ◽  
Author(s):  
Pablo J. Bruna ◽  
Friedrich Grein ◽  
Jack Passmore
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Ion Pairs ◽  
Dicarboxylic Acids ◽  
Polarizable Continuum Model ◽  
Weakly Bound ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Weakly Bound Complexes

The structures and stabilities of chainlike (CO2)n (n = 2–6) polycarbonates, where adjacent C atoms are linked by C–O–C bonds, were investigated at the density functional theory (DFT) level (B3PW91/6–311G(2d,p)), including dicarboxylic dianions, [CnO2n+1]2–, and the corresponding acids, [CnO2n+1]H2, and Li salts, [CnO2n+1]Li2. At equilibrium, the most stable systems have Cs, C2, or C2v symmetries. In the gas phase, these dianions are generally metastable with respect to spontaneous ejection of one electron, yet in the presence of counterions they become stabilized, for example, as [CnO2n+1]2–(Li+)2 ion pairs. [CnO2n+1]2– linkages are also stabilized as dicarboxylic acids, [CnO2n+1]H2; we find the latter to have equilibrium conformations of higher symmetry than previously reported in the literature. To the best of our knowledge, none of the [CnO2n+1]X2 (X = Li or H) compounds with n ≥ 2 have been reported in the experimental literature (albeit, the alkyl esters C2O5R2 and C3O7R2 are commercially available). All CO bonds in C2O5X2 to C6O13X2 have single- to double-bond character (≈140–118 pm), indicating that the [CnO2n+1] moieties are held together by strong chemical forces (in contrast to the weakly bound complexes (CO2)n and (CO2)n–, n > 1). Vibrational frequencies were calculated to ensure all conformations were true minima. The IR and Raman intensities show that the high intensity C=O stretching modes (1750 ± 100 cm–1) will help in the spectral characterization of these compounds. Solvation calculations using the polarizable continuum model (PCM) find that C2O52– can be formed via CO32– + CO2 as well as CO3–[Formula: see text], each reaction having ΔG298 < 0 in practically all solvents. This result confirms the experimentally observed large solubility of CO2(g) in molten carbonates, CO3M2 (M = Li, Na, or K). In contrast, starting with n = 2, the reactions [CnO2n+1]2– + CO2 do not proceed spontaneously in any solvent (ΔG298 > 0).

scholarly journals Ground- and excited-state characteristics in photovoltaic polymer N2200

RSC Advances ◽  
2021 ◽  
Author(s):  
Guanzhao Wen ◽  
Xianshao Zou ◽  
Rong Hu ◽  
Jun Peng ◽  
Zhifeng Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Steady State ◽  
Excited States ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Time Dependent ◽  
Functional Theory ◽  
Time Resolved ◽  
Dependent Density

Ground- and excited-states properties of N2200 have been studied by steady-state and time-resolved spectroscopies as well as time-dependent density functional theory calculations.

scholarly journals Corrigendum: Wavefunction in Density Functional Theory Embedding for Excited States: Which Wavefunctions, which Densities?

ChemPhysChem ◽  
2014 ◽  
Vol 15 (18) ◽  
pp. 3892-3892
Author(s):  
Csaba Daday ◽  
Carolin König ◽  
Johannes Neugebauer ◽  
Claudia Filippi
Keyword(s):  
Density Functional Theory ◽  
Excited States ◽  
Density Functional ◽  
Functional Theory

scholarly journals Density Functional Theory with Modified Dispersion Correction for Metals Applied to Self-Assembled Monolayers of Thiols on Au(111)

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
M. P. Andersson
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Dimethyl Disulfide ◽  
Gold Surface ◽  
Self Assembled Monolayers ◽  
Dispersion Correction ◽  
Dissociative Chemisorption ◽  
Functional Theory ◽  
Assembled Monolayers ◽  
Self Assembled

Using sound physical principles we modify the DFT-D2 atom pairwise semiempirical dispersion correction to density functional theory to work for metallic systems and in particular self-assembled monolayers of thiols on gold surfaces. We test our approximation for two functionals PBE-D and revPBE-D for lattice parameters and cohesive energies for Ni, Pd, Pt, Cu, Ag, and Au, adsorption energies of CO on (111) surfaces of Pd, Pt, Cu, Ag, and Au, and adsorption energy of benzene on Ag(111) and Au(111). Agreement with experimental data is substantially improved. We apply the method to self-assembled monolayers of alkanethiols on Au(111) and find reasonable agreement for PBE-D and revPBE-D for both physisorption of n-alkanethiols as well as dissociative chemisorption of dimethyl disulfide as an Au-adatom-dithiolate complex. By modifying the C6 coefficient for Au, we obtain quantitative agreement for physisorption and chemisorption for both PBE-D and revPBE-D using the same set of parameters. Our results confirm that inclusion of dispersion forces is crucial for any quantitative analysis of the thiol and thiolate bonds to the gold surface using quantum chemical calculations.

Multiconfiguration pair-density functional theory for doublet excitation energies and excited state geometries: the excited states of CN

2017 ◽  
Vol 19 (44) ◽  
pp. 30089-30096 ◽  
Author(s):  
Jie J. Bao ◽  
Laura Gagliardi ◽  
Donald G. Truhlar
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Excited States ◽  
Density Functional ◽  
Excitation Energies ◽  
Functional Theory ◽  
Pair Density

MC-PDFT is more accurate than CR-EOM-CCSD(T) or TDDFT when averaged over the first four adiabatic excitation energies of CN.

Sign in / Sign up

Export Citation Format

Share Document