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Decleva P, Fronzoni G, Stener M. Giant correlation effects in the photoelectron spectrum of Ni(C3H5)2: clues from accurate calculation of ionization cross-sections. Theor Chem Acc 2012. [DOI: 10.1007/s00214-012-1185-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Catone D, Stener M, Decleva P, Contini G, Zema N, Prosperi T, Feyer V, Prince KC, Turchini S. Resonant circular dichroism of chiral metal-organic complex. PHYSICAL REVIEW LETTERS 2012; 108:083001. [PMID: 22463525 DOI: 10.1103/physrevlett.108.083001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Indexed: 05/31/2023]
Abstract
A sizable enhancement of the circular dichroism in photoelectron spectroscopy has been measured and computed for the metal complex Δ-cobalt(III) tris-acetylacetonate highest occupied molecular orbital state in the region of the Co 3p→3d Fano resonance. In the resonance the dichroism reaches the maximum value of 5% and even changes its sign as compared to the direct photoionization channel. We ascribe this enhancement to electron correlation processes, namely, with the coupling between discrete excitations and the continuum, which is correctly described in the time dependent density functional theory (TDDFT) framework. These findings open new physical aspects of photoelectron circular dichroism that now can be interpreted not only via the simple direct ionization, but also through more complex electron correlation processes.
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Mizuno T, Adachi J, Miyauchi N, Kazama M, Stener M, Decleva P, Yagishita A. Recoil frame photoelectron angular distributions of BF3: A sensitive probe of the shape resonance in the F 1s continuum. J Chem Phys 2012; 136:074305. [DOI: 10.1063/1.3687006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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29
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Holland D, Potts A, Karlsson L, Stener M, Decleva P. A study of the valence shell photoionisation dynamics of pyrimidine and pyrazine. Chem Phys 2011. [DOI: 10.1016/j.chemphys.2011.09.025] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Stranges S, Alagia M, Decleva P, Stener M, Fronzoni G, Toffoli D, Speranza M, Catone D, Turchini S, Prosperi T, Zema N, Contini G, Keheyan Y. The valence electronic structure and conformational flexibility of epichlorohydrin. Phys Chem Chem Phys 2011; 13:12517-28. [PMID: 21666904 DOI: 10.1039/c0cp02730h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The electronic structure of epichlorohydrin is investigated in the whole valence region by a combined experimental and theoretical study. The issue of controversial assignments of the molecular electronic structure is here addressed. Photoelectron spectra (PES) and Threshold Photoelectron spectra (TPES) of room temperature molecules in the gas phase are recorded. Geometries and energies of the stable conformers due to internal rotation of the C-C-C-Cl dihedral angle, gauche-II (g-II), gauche-I (g-I), and cis, are calculated, and the effect of the conformational flexibility on the photoionization energetics is studied by DFT and 2h-1p Configuration Interaction (CI) methods. Strong breakdown of the Koopmans Theorem (KT) is obtained for the four outermost ionizations, which are further investigated by higher level ab initio calculations. The full assignment of the spectrum is put on a firm basis by the combination of experimental and theoretical results. The orbital composition from correlated calculations is found closer to the DFT orbitals, which are then used to analyze the electronic structure of the molecule. The Highest Occupied Molecular Orbital (HOMO) and HOMO--2 are n(O)/n(Cl) mixed orbitals. The nature of each valence MO is generally preserved in all the conformers, although the magnitude of the n(O)/n(Cl) mixing in HOMO and HOMO--2 varies to some extent with the C-C-C-Cl dihedral angle. The low energy part of the HOMO PE band is predicted to be substantially affected by the conformational flexibility, as experimentally observed in the spectra. The rest of the spectrum is described in terms of the dominant conformer g-II, and a good agreement between experiment and theory is found. The inner-valence PE spectrum is characterized by satellite structures, due to electron correlation effects, which are interpreted by means of 2h-1p CI calculations.
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Stener M, Bolognesi P, Coreno M, O’Keeffe P, Feyer V, Fronzoni G, Decleva P, Avaldi L, Kivimäki A. Photoabsorption and S 2p photoionization of the SF6 molecule: Resonances in the excitation energy range of 200–280 eV. J Chem Phys 2011; 134:174311. [DOI: 10.1063/1.3583815] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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32
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Kivimäki A, Álvarez-Ruiz J, Coreno M, Stankiewicz M, Fronzoni G, Stener M, Decleva P. S 2p photoabsorption of the SF5CF3 molecule: Experiment, theory and comparison with SF6. Chem Phys 2010. [DOI: 10.1016/j.chemphys.2010.07.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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33
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Stener M, Fronzoni G, Decleva P. Time Dependent Density Functional Theory description of giant resonances in transition metal complexes: The photoionization dynamics of Cr(CO)6. Chem Phys 2009. [DOI: 10.1016/j.chemphys.2009.05.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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Fronzoni G, Stener M, Decleva P, Simone MD, Coreno M, Franceschi P, Furlani C, Prince KC. X-ray Absorption Spectroscopy of VOCl3, CrO2Cl2, and MnO3Cl: An Experimental and Theoretical Study. J Phys Chem A 2009; 113:2914-25. [DOI: 10.1021/jp808720z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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35
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Fukuzawa H, Liu XJ, Teranishi T, Sakai K, Prümper G, Ueda K, Morishita Y, Saito N, Stener M, Decleva P. Fluorine K-shell photoelectron angular distribution from CF4 molecules in the molecular frame. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2007.11.085] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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36
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Toffoli D, Decleva P, Gianturco FA, Lucchese RR. Density functional theory for the photoionization dynamics of uracil. J Chem Phys 2007; 127:234317. [DOI: 10.1063/1.2813349] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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37
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Catone D, Turchini S, Contini G, Zema N, Irrera S, Prosperi T, Stener M, Di Tommaso D, Decleva P. 2-amino-1-propanol versus 1-amino-2-propanol: Valence band and C 1s core-level photoelectron spectra. J Chem Phys 2007; 127:144312. [DOI: 10.1063/1.2798113] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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38
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Fronzoni G, De Francesco R, Stener M, Decleva P. Spin-orbit relativistic calculations of the core excitation spectra of SO2. J Chem Phys 2007; 126:134308. [PMID: 17430033 DOI: 10.1063/1.2713744] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The time dependent density functional theory approach within the two-component zero-order relativistic approximation has been applied to the calculation of the core excitation spectra of SO2 molecule. The results obtained reproduce correctly the high resolution experimental spectra and allow the assignment of the spectral features both of the valence and Rydberg regions in the S 1s and O 1s spectra. For the S 2p threshold a correct description of the spin-orbit coupling as well as of the molecular field splitting appears mandatory for a reliable description of the spectrum and a detailed attribution of the complex Rydberg manifold of core excited states.
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Stranges S, Turchini S, Alagia M, Alberti G, Contini G, Decleva P, Fronzoni G, Stener M, Zema N, Prosperi T. Valence photoionization dynamics in circular dichroism of chiral free molecules: the methyl-oxirane. J Chem Phys 2007; 122:244303. [PMID: 16035753 DOI: 10.1063/1.1940632] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The dynamical behavior of circular dichroism for valence photoionization processes in pure enantiomers of randomly oriented methyl-oxirane molecules has been studied by circularly polarized synchrotron radiation. Experimental results of the dichroism coefficient obtained for valence photoionization processes as a function of photon energy have been compared with theoretical values predicted by state-of-the-art ab initio density-functional theory. The circular dichroism measured at low electron kinetic energies was as large as 11%. Trends in the experimental dynamical behavior of the dichroism coefficients D(i)(omega) have been observed. Agreement between experimental and theoretical results permits unambiguous identification of the enantiomer and of the individual orbitals.
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Stener M, Toffoli D, Fronzoni G, Decleva P. Recent advances in molecular photoionization by density functional theory based approaches. Theor Chem Acc 2006. [DOI: 10.1007/s00214-006-0212-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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41
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Toffoli D, Stener M, Fronzoni G, Decleva P. Photoionization cross section and angular distribution calculations of carbon tetrafluoride. J Chem Phys 2006; 124:214313. [PMID: 16774413 DOI: 10.1063/1.2204033] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Correlation in the photoionization dynamics of carbon tetrafluoride is studied in the framework of the time-dependent density-functional theory (TDDFT) approach by employing a multicentric basis set expansion of the scattering wave function linear combination of atomic orbitals (LCAO) TDDFT. Results obtained with the statistical average of orbital potentials and LB94 exchange-correlation (xc) potentials are compared with photoabsorption, photoionization, and electron-scattering experiments as well as with past theoretical calculations. Inadequacies in both the V(xc) parametrizations employed have been suggested from the analysis of the intensity plots for the D2A1 ionization. The formation of resonant scattering states in selected continuum channels has been studied through the analysis of the dipole-prepared scattering wave function; our findings are then compared with results of electron-scattering calculations. Overall, the LCAO-TDDFT results highlight the effectiveness of the approach for the calculation of the unbound spectrum of fairly large molecules.
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Stener M, Toffoli D, Fronzoni G, Decleva P. Time dependent density functional study of the photoionization dynamics of SF6. J Chem Phys 2006; 124:114306. [PMID: 16555887 DOI: 10.1063/1.2178799] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The B-spline linear combination of atomic orbitals method has been employed to study the valence and core photoionization dynamics of SF6. The cross section and asymmetry parameter profiles calculated at the time dependent density functional theory level have been found to be in fairly nice agreement with the experimental data, with the quality of the exchange-correlation statistical average of orbital potential results superior to the Van Leeuwen-Baerends 94 (LB94) ones [Phys. Rev. A 49, 2421 (1994)]. The role of response effects has been identified by a comparison of the time dependent density functional theory results with the Kohn-Sham ones interchannel coupling effects and autoionization resonances play an important role at low kinetic energies. Prominent shape resonances features have been analyzed in terms of "dipole prepared" continuum orbitals and interpreted as due to a large angular momentum centrifugal barrier as well as anisotropic (nonspherical) molecular effective potential. Finally, the method has been proven numerically stable, robust, and efficient, thanks to a noniterative implementation of the time dependent density functional theory equations and suitability of the multicentric B-spline basis set to describe continuum states from outer valence to deep core states.
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Stener M, Di Tommaso D, Fronzoni G, Decleva P, Powis I. Theoretical study on the circular dichroism in core and valence photoelectron angular distributions of camphor enantiomers. J Chem Phys 2006; 124:024326. [PMID: 16422602 DOI: 10.1063/1.2150438] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In the present work the photoelectron circular dichroism of camphor has been theoretically studied using B-spline and continuum multiple scattering-Xalpha methods, and comparisons are made with available experimental data. In general, rather large dichroism effects have been found for both valence and core (O 1s, C 1s) photoionizations. The agreement between the two calculations reported here and previous experimental measurements for core C 1s data is essentially quantitative. For valence ionization satisfactory agreement between theory and experiment has been obtained and the discrepancies have been attributed to both exchange-correlation potential limitations and the absence of response effects in the adopted formalism. The calculations predict, moreover, important features in the cross-section profiles, which have been discussed in terms of dipole-prepared continuum orbitals.
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Stener M, Fronzoni G, Decleva P. Time-dependent density-functional theory for molecular photoionization with noniterative algorithm and multicenter B-spline basis set: CS2 and C6H6 case studies. J Chem Phys 2005; 122:234301. [PMID: 16008435 DOI: 10.1063/1.1937367] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this work a new direct (noniterative) algorithm to solve the time-dependent density-functional theory equations for molecular photoionization has been proposed and implemented, using a multicentric basis set expansion of B-spline functions and complete exploiting of the molecular point-group symmetry. The method has been applied to study the photoionization dynamics of CS2 and C6H6: the results confirmed the expectation of large screening effects in CS2. For C6H6 the screening effects have been found to play a minor role than in CS2, however, also in this case the quality of the final results is definitely improved. The method has proven suitable to study with confidence molecules of medium size, and there is still room for further improvement working on more elaborate treatment of the exchange-correlation functional.
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Fronzoni G, Stener M, Reduce A, Decleva P. Time-Dependent Density Functional Theory Calculations of Ligand K Edge and Metal L Edge X-ray Absorption of a Series of Oxomolybdenum Complexes. J Phys Chem A 2004. [DOI: 10.1021/jp047953u] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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46
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Fronzoni G, Stener M, Decleva P. Valence and core photoionization dynamics of acetylene by TD-DFT continuum approach. Chem Phys 2004. [DOI: 10.1016/j.chemphys.2003.11.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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47
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Stener M, Fronzoni G, Tommaso DD, Decleva P. Density functional study on the circular dichroism of photoelectron angular distribution from chiral derivatives of oxirane. J Chem Phys 2004; 120:3284-96. [PMID: 15268483 DOI: 10.1063/1.1640617] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The linear combination of atomic orbitals B-spline density functional method has been successfully applied to a series of four chiral derivatives of oxirane, to calculate the photoionization dynamical parameters, the circular dichroism in the angular distribution effect, and to identify trends along the series. The computational algorithm has proven numerically stable and computationally competitive. The photoionization cross section, asymmetry, and dichroic parameter profiles relative to valence orbitals have been systematically studied for the states which retain their nature along the series: the identified trends have been ascribed to the different electronic properties of the substituents. A rather unexpected sensitivity of the dichroic parameter to changes in the electronic structure has been found in many instances, making this dynamical property suitable to investigate the electronic structure of chiral compounds. The magnitude of the circular dichroism in the angular distribution effect does not seem to be associated with the initial state chirality, but rather to be governed by the ability of the delocalized photoelectron wave function to probe the asymmetry of the molecular effective potential.
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Fronzoni G, Stener M, Decleva P. Dramatic response effects in the photoionization of the second-row hydrides: A time-dependent density functional investigation. J Chem Phys 2003. [DOI: 10.1063/1.1572451] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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49
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Fronzoni G, Coreno M, de Simone M, Franceschi P, Furlani C, Furlan S, Prince KC, Stener M, Decleva P. High resolution inner-shell spectroscopy and ab initio CI calculations on TiCl4 and isoelectronic moleculesElectronic supplementary information (ESI) available: All excitation energies and oscillator strengths for TiCl4, VOCl3, CrO2Cl2 and MnO3Cl, including Rydberg levels. See http://www.rsc.org/suppdata/cp/b3/b302805b/. Phys Chem Chem Phys 2003. [DOI: 10.1039/b302805b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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50
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Stener M, Fronzoni G, Toffoli D, Decleva P. Time dependent density functional photoionization of CH4, NH3, H2O and HF. Chem Phys 2002. [DOI: 10.1016/s0301-0104(02)00726-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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