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Hiroshi Nakatsuji - One of the best experts on this subject based on the ideXlab platform.
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excited state geometries and vibrational frequencies studied using the analytical energy gradients of the direct symmetry adapted Cluster Configuration interaction method i hax type molecules
Journal of Chemical Physics, 2011Co-Authors: Masahiro Ehara, Ryoichi Fukuda, Fumito Oyagi, Yoko Abe, Hiroshi NakatsujiAbstract:In this series of studies, we systematically apply the analytical energy gradients of the direct symmetry-adapted Cluster-Configuration interaction singles and doubles nonvariational method to calculate the equilibrium geometries and vibrational frequencies of excited and ionized states of molecules. The harmonic vibrational frequencies were calculated using the second derivatives numerically computed from the analytical first derivatives and the anharmonicity was evaluated from the three-dimensional potential energy surfaces around the local minima. In this paper, the method is applied to the low-lying valence singlet and triplet excited states of HAX-type molecules, HCF, HCCl, HSiF, HSiCl, HNO, HPO, and their deuterium isotopomers. The vibrational level emission spectra of HSiF and DSiF and absorption spectra of HSiCl and DSiCl were also simulated within the Franck-Condon approximation and agree well with the experimental spectra. The results show that the present method is useful and reliable for calculating these quantities and spectra. The change in geometry in the excited states was qualitatively interpreted in the light of the electrostatic force theory. The effect of perturbation selection with the localized molecular orbitals on the geometrical parameters and harmonic vibrational frequencies is also discussed.
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nonequilibrium solvation for vertical photoemission and photoabsorption processes using the symmetry adapted Cluster Configuration interaction method in the polarizable continuum model
Journal of Chemical Physics, 2011Co-Authors: Ryoichi Fukuda, Masahiro Ehara, Hiroshi Nakatsuji, Roberto CammiAbstract:In this paper, we present the theory and implementation of a nonequilibrium solvation model for the symmetry-adapted Cluster (SAC) and symmetry-adapted Cluster–Configuration interaction (SAC–CI) method in the polarizable continuum model. For nonequilibrium solvation, we adopted the Pekar partition scheme in which solvent charges are divided into dynamical and inertial components. With this nonequilibrium solvation scheme, a vertical transition from an initial state to a final state may be described as follows: the initial state is described by equilibrium solvation, while in the final state, the inertial component remains in the solvation for the initial state; the dynamical component will be calculated self-consistently for the final state. The present method was applied to the vertical photoemission and absorption of s-trans acrolein and methylenecyclopropene. The effect of nonequilibrium solvation was significant for a polar solvent.
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symmetry adapted Cluster and symmetry adapted Cluster Configuration interaction method in the polarizable continuum model theory of the solvent effect on the electronic excitation of molecules in solution
Journal of Chemical Physics, 2010Co-Authors: Roberto Cammi, Ryoichi Fukuda, Masahiro Ehara, Hiroshi NakatsujiAbstract:In this paper we present the theory and implementation of the symmetry-adapted Cluster (SAC) and symmetry-adapted Cluster-Configuration interaction (SAC-CI) method, including the solvent effect, using the polarizable continuum model (PCM). The PCM and SAC/SAC-CI were consistently combined in terms of the energy functional formalism. The excitation energies were calculated by means of the state-specific approach, the advantage of which over the linear-response approach has been shown. The single-point energy calculation and its analytical energy derivatives are presented and implemented, where the free-energy and its derivatives are evaluated because of the presence of solute-solvent interactions. We have applied this method to s-trans-acrolein and metylenecyclopropene of their electronic excitation in solution. The molecular geometries in the ground and excited states were optimized in vacuum and in solution, and both the vertical and adiabatic excitations were studied. The PCM-SAC/SAC-CI reproduced the k...
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symmetry adapted Cluster and symmetry adapted Cluster Configuration interaction method in the polarizable continuum model theory of the solvent effect on the electronic excitation of molecules in solution
Journal of Chemical Physics, 2010Co-Authors: Roberto Cammi, Ryoichi Fukuda, Masahiro Ehara, Hiroshi NakatsujiAbstract:In this paper we present the theory and implementation of the symmetry-adapted Cluster (SAC) and symmetry-adapted Cluster-Configuration interaction (SAC-CI) method, including the solvent effect, using the polarizable continuum model (PCM). The PCM and SAC/SAC-CI were consistently combined in terms of the energy functional formalism. The excitation energies were calculated by means of the state-specific approach, the advantage of which over the linear-response approach has been shown. The single-point energy calculation and its analytical energy derivatives are presented and implemented, where the free-energy and its derivatives are evaluated because of the presence of solute-solvent interactions. We have applied this method to s-trans-acrolein and metylenecyclopropene of their electronic excitation in solution. The molecular geometries in the ground and excited states were optimized in vacuum and in solution, and both the vertical and adiabatic excitations were studied. The PCM-SAC/SAC-CI reproduced the known trend of the solvent effect on the vertical excitation energies but the shift values were underestimated. The excited state geometry in planar and nonplanar conformations was investigated. The importance of using state-specific methods was shown for the solvent effect on the optimized geometry in the excited state. The mechanism of the solvent effect is discussed in terms of the Mulliken charges and electronic dipole moment.
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valence ionized states of iron pentacarbonyl and η5 cyclopentadienyl cobalt dicarbonyl studied by symmetry adapted Cluster Configuration interaction calculation and collision energy resolved penning ionization electron spectroscopy
Journal of Chemical Physics, 2010Co-Authors: Ryoichi Fukuda, Masahiro Ehara, Hiroshi Nakatsuji, Naoki Kishimoto, Koichi OhnoAbstract:Valence ionized states of iron pentacarbonyl Fe(CO)5 and η5-cyclopentadienyl cobalt dicarbonyl Co(η5-C5H5)(CO)2 have been studied by ultraviolet photoelectron spectroscopy, two-dimensional Penning ionization electron spectroscopy (2D-PIES), and symmetry-adapted Cluster-Configuration interaction calculations. Theory provided reliable assignments for the complex ionization spectra of these molecules, which have metal-carbonyl bonds. Theoretical ionization energies agreed well with experimental observations and the calculated wave functions could explain the relative intensities of PIES spectra. The collision-energy dependence of partial ionization cross sections (CEDPICS) was obtained by 2D-PIES. To interpret these CEDPICS, the interaction potentials between the molecules and a Li atom were examined in several coordinates by calculations. The relation between the slope of the CEDPICS and the electronic structure of the ionized states, such as molecular symmetry and the spatial distribution of ionizing orbit...
Masahiro Ehara - One of the best experts on this subject based on the ideXlab platform.
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an efficient computational scheme for electronic excitation spectra of molecules in solution using the symmetry adapted Cluster Configuration interaction method the accuracy of excitation energies and intuitive charge transfer indices
Journal of Chemical Physics, 2014Co-Authors: Ryoichi Fukuda, Masahiro EharaAbstract:Solvent effects on electronic excitation spectra are considerable in many situations; therefore, we propose an efficient and reliable computational scheme that is based on the symmetry-adapted Cluster-Configuration interaction (SAC-CI) method and the polarizable continuum model (PCM) for describing electronic excitations in solution. The new scheme combines the recently proposed first-order PCM SAC-CI method with the PTE (perturbation theory at the energy level) PCM SAC scheme. This is essentially equivalent to the usual SAC and SAC-CI computations with using the PCM Hartree-Fock orbital and integrals, except for the additional correction terms that represent solute-solvent interactions. The test calculations demonstrate that the present method is a very good approximation of the more costly iterative PCM SAC-CI method for excitation energies of closed-shell molecules in their equilibrium geometry. This method provides very accurate values of electric dipole moments but is insufficient for describing the charge-transfer (CT) indices in polar solvent. The present method accurately reproduces the absorption spectra and their solvatochromism of push-pull type 2,2′-bithiophene molecules. Significant solvent and substituent effects on these molecules are intuitively visualized using the CT indices. The present method is the simplest and theoretically consistent extension of SAC-CI method for including PCM environment, and therefore, it is useful for theoretical and computational spectroscopy.
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d d π a type organic dyes for dye sensitized solar cells with a potential for direct electron injection and a high extinction coefficient synthesis characterization and theoretical investigation
Journal of Physical Chemistry C, 2012Co-Authors: Supawadee Namuangruk, Ryoichi Fukuda, Masahiro Ehara, Jittima Meeprasert, Tanika Khanasa, Somphob Morada, Tinnagon Kaewin, Siriporn Jungsuttiwong, Taweesak Sudyoadsuk, Vinich PromarakAbstract:A series of organic sensitizers with the direct electron injection mechanism and a high molar extinction coefficient comprising double donors, a π-spacer, and anchoring acceptor groups (D–D−π–A type) were synthesized and characterized by experimental and theoretical methods for dye-sensitized solar cells. (E)-2-Cyano-3-(5″-(4-((4-(3,6-di-tert-butylcarbazol-9-yl)phenyl)dodecylamino)phenyl)-[2,2′:5′,2″-terthiophene]-5-yl)acrylic acid showed performance with a maximal incident photon to electron conversion efficiency of 83%, Jsc value of 10.89 mA cm–2, Voc value of 0.70 V, and fill factor of 0.67, which correspond to an overall conversion efficiency of 5.12% under AM 1.5G illumination. The molecular geometry, electronic structure, and excited states were investigated with density functional theory, time-dependent density functional theory, and the symmetry-adapted Cluster-Configuration interaction method. The double donor moieties not only contribute to enhancement of the electron-donating ability, but also ...
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elucidating electronic transitions from σ orbitals of liquid n and branched alkanes by far ultraviolet spectroscopy and quantum chemical calculations
Journal of Physical Chemistry A, 2012Co-Authors: Yusuke Morisawa, Masahiro Ehara, Shin Tachibana, Yukihiro OzakiAbstract:Attenuated total reflection far-ultraviolet (ATR-FUV) spectra containing Rydberg states of n-alkanes (CmH2m+2; m varies in the range 5–9) and branched alkanes observed in the liquid phase were investigated by quantum chemical calculations with the aim of elucidating electronic transitions from σ orbitals of liquid n- and branched alkanes. New assignments are proposed based on the time-dependent density functional theory (TD-DFT) and symmetry-adapted Cluster Configuration interaction (SAC-CI) calculations, and the differences in these spectra are analyzed in detail. The FUV spectra of n-alkanes show a broad asymmetric feature near 8.3 eV. The strong band at ∼8.3 eV shows a red shift with a significant increase in intensity as the carbon chain length increases, which is attributed to the overlapping transitions from the third (or fourth) highest occupied molecular orbitals HOMO–2 (or HOMO–3) and HOMO–1 to Rydberg 3py by the TD-DFT and SAC-CI calculations. This band was previously assigned to the overlap of ...
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excited state geometries and vibrational frequencies studied using the analytical energy gradients of the direct symmetry adapted Cluster Configuration interaction method i hax type molecules
Journal of Chemical Physics, 2011Co-Authors: Masahiro Ehara, Ryoichi Fukuda, Fumito Oyagi, Yoko Abe, Hiroshi NakatsujiAbstract:In this series of studies, we systematically apply the analytical energy gradients of the direct symmetry-adapted Cluster-Configuration interaction singles and doubles nonvariational method to calculate the equilibrium geometries and vibrational frequencies of excited and ionized states of molecules. The harmonic vibrational frequencies were calculated using the second derivatives numerically computed from the analytical first derivatives and the anharmonicity was evaluated from the three-dimensional potential energy surfaces around the local minima. In this paper, the method is applied to the low-lying valence singlet and triplet excited states of HAX-type molecules, HCF, HCCl, HSiF, HSiCl, HNO, HPO, and their deuterium isotopomers. The vibrational level emission spectra of HSiF and DSiF and absorption spectra of HSiCl and DSiCl were also simulated within the Franck-Condon approximation and agree well with the experimental spectra. The results show that the present method is useful and reliable for calculating these quantities and spectra. The change in geometry in the excited states was qualitatively interpreted in the light of the electrostatic force theory. The effect of perturbation selection with the localized molecular orbitals on the geometrical parameters and harmonic vibrational frequencies is also discussed.
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nonequilibrium solvation for vertical photoemission and photoabsorption processes using the symmetry adapted Cluster Configuration interaction method in the polarizable continuum model
Journal of Chemical Physics, 2011Co-Authors: Ryoichi Fukuda, Masahiro Ehara, Hiroshi Nakatsuji, Roberto CammiAbstract:In this paper, we present the theory and implementation of a nonequilibrium solvation model for the symmetry-adapted Cluster (SAC) and symmetry-adapted Cluster–Configuration interaction (SAC–CI) method in the polarizable continuum model. For nonequilibrium solvation, we adopted the Pekar partition scheme in which solvent charges are divided into dynamical and inertial components. With this nonequilibrium solvation scheme, a vertical transition from an initial state to a final state may be described as follows: the initial state is described by equilibrium solvation, while in the final state, the inertial component remains in the solvation for the initial state; the dynamical component will be calculated self-consistently for the final state. The present method was applied to the vertical photoemission and absorption of s-trans acrolein and methylenecyclopropene. The effect of nonequilibrium solvation was significant for a polar solvent.
Ryoichi Fukuda - One of the best experts on this subject based on the ideXlab platform.
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an efficient computational scheme for electronic excitation spectra of molecules in solution using the symmetry adapted Cluster Configuration interaction method the accuracy of excitation energies and intuitive charge transfer indices
Journal of Chemical Physics, 2014Co-Authors: Ryoichi Fukuda, Masahiro EharaAbstract:Solvent effects on electronic excitation spectra are considerable in many situations; therefore, we propose an efficient and reliable computational scheme that is based on the symmetry-adapted Cluster-Configuration interaction (SAC-CI) method and the polarizable continuum model (PCM) for describing electronic excitations in solution. The new scheme combines the recently proposed first-order PCM SAC-CI method with the PTE (perturbation theory at the energy level) PCM SAC scheme. This is essentially equivalent to the usual SAC and SAC-CI computations with using the PCM Hartree-Fock orbital and integrals, except for the additional correction terms that represent solute-solvent interactions. The test calculations demonstrate that the present method is a very good approximation of the more costly iterative PCM SAC-CI method for excitation energies of closed-shell molecules in their equilibrium geometry. This method provides very accurate values of electric dipole moments but is insufficient for describing the charge-transfer (CT) indices in polar solvent. The present method accurately reproduces the absorption spectra and their solvatochromism of push-pull type 2,2′-bithiophene molecules. Significant solvent and substituent effects on these molecules are intuitively visualized using the CT indices. The present method is the simplest and theoretically consistent extension of SAC-CI method for including PCM environment, and therefore, it is useful for theoretical and computational spectroscopy.
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d d π a type organic dyes for dye sensitized solar cells with a potential for direct electron injection and a high extinction coefficient synthesis characterization and theoretical investigation
Journal of Physical Chemistry C, 2012Co-Authors: Supawadee Namuangruk, Ryoichi Fukuda, Masahiro Ehara, Jittima Meeprasert, Tanika Khanasa, Somphob Morada, Tinnagon Kaewin, Siriporn Jungsuttiwong, Taweesak Sudyoadsuk, Vinich PromarakAbstract:A series of organic sensitizers with the direct electron injection mechanism and a high molar extinction coefficient comprising double donors, a π-spacer, and anchoring acceptor groups (D–D−π–A type) were synthesized and characterized by experimental and theoretical methods for dye-sensitized solar cells. (E)-2-Cyano-3-(5″-(4-((4-(3,6-di-tert-butylcarbazol-9-yl)phenyl)dodecylamino)phenyl)-[2,2′:5′,2″-terthiophene]-5-yl)acrylic acid showed performance with a maximal incident photon to electron conversion efficiency of 83%, Jsc value of 10.89 mA cm–2, Voc value of 0.70 V, and fill factor of 0.67, which correspond to an overall conversion efficiency of 5.12% under AM 1.5G illumination. The molecular geometry, electronic structure, and excited states were investigated with density functional theory, time-dependent density functional theory, and the symmetry-adapted Cluster-Configuration interaction method. The double donor moieties not only contribute to enhancement of the electron-donating ability, but also ...
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excited state geometries and vibrational frequencies studied using the analytical energy gradients of the direct symmetry adapted Cluster Configuration interaction method i hax type molecules
Journal of Chemical Physics, 2011Co-Authors: Masahiro Ehara, Ryoichi Fukuda, Fumito Oyagi, Yoko Abe, Hiroshi NakatsujiAbstract:In this series of studies, we systematically apply the analytical energy gradients of the direct symmetry-adapted Cluster-Configuration interaction singles and doubles nonvariational method to calculate the equilibrium geometries and vibrational frequencies of excited and ionized states of molecules. The harmonic vibrational frequencies were calculated using the second derivatives numerically computed from the analytical first derivatives and the anharmonicity was evaluated from the three-dimensional potential energy surfaces around the local minima. In this paper, the method is applied to the low-lying valence singlet and triplet excited states of HAX-type molecules, HCF, HCCl, HSiF, HSiCl, HNO, HPO, and their deuterium isotopomers. The vibrational level emission spectra of HSiF and DSiF and absorption spectra of HSiCl and DSiCl were also simulated within the Franck-Condon approximation and agree well with the experimental spectra. The results show that the present method is useful and reliable for calculating these quantities and spectra. The change in geometry in the excited states was qualitatively interpreted in the light of the electrostatic force theory. The effect of perturbation selection with the localized molecular orbitals on the geometrical parameters and harmonic vibrational frequencies is also discussed.
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nonequilibrium solvation for vertical photoemission and photoabsorption processes using the symmetry adapted Cluster Configuration interaction method in the polarizable continuum model
Journal of Chemical Physics, 2011Co-Authors: Ryoichi Fukuda, Masahiro Ehara, Hiroshi Nakatsuji, Roberto CammiAbstract:In this paper, we present the theory and implementation of a nonequilibrium solvation model for the symmetry-adapted Cluster (SAC) and symmetry-adapted Cluster–Configuration interaction (SAC–CI) method in the polarizable continuum model. For nonequilibrium solvation, we adopted the Pekar partition scheme in which solvent charges are divided into dynamical and inertial components. With this nonequilibrium solvation scheme, a vertical transition from an initial state to a final state may be described as follows: the initial state is described by equilibrium solvation, while in the final state, the inertial component remains in the solvation for the initial state; the dynamical component will be calculated self-consistently for the final state. The present method was applied to the vertical photoemission and absorption of s-trans acrolein and methylenecyclopropene. The effect of nonequilibrium solvation was significant for a polar solvent.
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symmetry adapted Cluster and symmetry adapted Cluster Configuration interaction method in the polarizable continuum model theory of the solvent effect on the electronic excitation of molecules in solution
Journal of Chemical Physics, 2010Co-Authors: Roberto Cammi, Ryoichi Fukuda, Masahiro Ehara, Hiroshi NakatsujiAbstract:In this paper we present the theory and implementation of the symmetry-adapted Cluster (SAC) and symmetry-adapted Cluster-Configuration interaction (SAC-CI) method, including the solvent effect, using the polarizable continuum model (PCM). The PCM and SAC/SAC-CI were consistently combined in terms of the energy functional formalism. The excitation energies were calculated by means of the state-specific approach, the advantage of which over the linear-response approach has been shown. The single-point energy calculation and its analytical energy derivatives are presented and implemented, where the free-energy and its derivatives are evaluated because of the presence of solute-solvent interactions. We have applied this method to s-trans-acrolein and metylenecyclopropene of their electronic excitation in solution. The molecular geometries in the ground and excited states were optimized in vacuum and in solution, and both the vertical and adiabatic excitations were studied. The PCM-SAC/SAC-CI reproduced the k...
Along Liu - One of the best experts on this subject based on the ideXlab platform.
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ho2o c74 ho2o Cluster expands within a small non ipr fullerene cage of c2 13333 c74
Inorganic Chemistry, 2019Co-Authors: Along Liu, Mingzhe Nie, Yajuan Hao, Ying Yang, Taishan Wang, Zdenek Slanina, Hailin Cong, Lai Feng, Chunru WangAbstract:Steering the Cluster Configuration inside a fullerene cage has been one of most interesting topics in the field of fullerenes, since the physical property of a Cluster fullerene may be modified accordingly. It has been well-recognized that the Cluster Configuration can be tuned via altering the cage size. Typically, the carbide Cluster and the oxide Cluster are experimentally seen to be curled up within a small fullerene cage whereas they are expanded in a large cage. In this work, a new oxide Cluster fullerene Ho2O@C2(13333)-C74 is prepared and isolated. The single-crystal X-ray diffraction (XRD) study reveals that the Ho2O Cluster, however, expands within the small non-IPR cage of C2(13333)-C74 with a Ho–O–Ho angle of >170°, indicating that Cluster Configuration is highly related to the cage shape and cage structure as well. The DFT computation demonstrates that the Cluster-to-cage electron-transfer obviously enhances the aromaticity of the motif containing the fused-pentagon pair and hence stabilizes t...
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Ho2O@C74: Ho2O Cluster Expands within a Small Non-IPR Fullerene Cage of C2(13333)‑C74
2019Co-Authors: Along Liu, Mingzhe Nie, Yajuan Hao, Ying Yang, Taishan Wang, Zdenek Slanina, Hailin Cong, Lai Feng, Chunru Wang, Filip UhlíkAbstract:Steering the Cluster Configuration inside a fullerene cage has been one of most interesting topics in the field of fullerenes, since the physical property of a Cluster fullerene may be modified accordingly. It has been well-recognized that the Cluster Configuration can be tuned via altering the cage size. Typically, the carbide Cluster and the oxide Cluster are experimentally seen to be curled up within a small fullerene cage whereas they are expanded in a large cage. In this work, a new oxide Cluster fullerene Ho2O@C2(13333)-C74 is prepared and isolated. The single-crystal X-ray diffraction (XRD) study reveals that the Ho2O Cluster, however, expands within the small non-IPR cage of C2(13333)-C74 with a Ho–O–Ho angle of >170°, indicating that Cluster Configuration is highly related to the cage shape and cage structure as well. The DFT computation demonstrates that the Cluster-to-cage electron-transfer obviously enhances the aromaticity of the motif containing the fused-pentagon pair and hence stabilizes the non-IPR cage of C2(13333)-C74. In addition, the electrochemical and magnetic properties of Ho2O@C2(13333)-C74 are studied to further investigate the effect of endohedral Ho2O Cluster
Junya Hasegawa - One of the best experts on this subject based on the ideXlab platform.
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circular dichroism and absorption spectroscopy for three membered ring compounds using symmetry adapted Cluster Configuration interaction sac ci method
Bulletin of the Chemical Society of Japan, 2009Co-Authors: Tomoo Miyahara, Junya Hasegawa, Hiroshi NakatsujiAbstract:The singlet excited states of oxirane and thiirane derivatives, ethylene oxide, (R)-methyloxirane, (2S,3S)-dimethyloxirane, ethylene sulfide, (R)-methylthiirane, and (2S,3S)-dimethylthiirane, were ...
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artificial color tuning of firefly luminescence theoretical mutation by tuning electrostatic interactions between protein and luciferin
Chemical Physics Letters, 2009Co-Authors: Naoki Nakatani, Junya Hasegawa, Hiroshi NakatsujiAbstract:Abstract Electrostatic interactions between firefly oxyluciferin and the surrounding proteins were analyzed, and the amino acids important for controlling emission energy were identified. We propose Arg223Ala, Glu344Ala, and Asp422Ala mutations in firefly oxyluciferase of Photinus pyralis , which artificially change the luminescence color by tuning the electrostatic effect from the luciferase proteins. In the theoretical mutation simulation, the emission energy of the triple mutant was estimated to be 2.05 eV (602 nm, reddish-orange), which is 0.18 eV lower than that of the wild type (2.23 eV, 557 nm, yellow–green). For calculating the emission energies, we used the symmetry-adapted Cluster-Configuration interaction (SAC-CI) method.
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red light in chemiluminescence and yellow green light in bioluminescence color tuning mechanism of firefly photinus pyralis studied by the symmetry adapted Cluster Configuration interaction method
Journal of the American Chemical Society, 2007Co-Authors: Naoki Nakatani, Junya Hasegawa, Hiroshi NakatsujiAbstract:The yellow-green luminescence from firefly luciferase has long been understood to be the emission from enol-oxyluciferin. However, a recent experiment showed that an oxyluciferin constrained to the keto form produced a yellow-green emission in luciferase (Branchini, B. R.; Murtiashaw, M. H.; Magyar, R. A.; Portier, N. C.; Ruggiero, M. C.; Stroh, J. G. J. Am. Chem. Soc. 2002, 124, 2112-2113). The present quantum mechanical/molecular mechanical and symmetry-adapted Cluster−Configuration interaction (SAC−CI) theoretical study supports the keto-form to be the yellow-green bioluminescence state in luciferase. We give the theoretically optimized structure of the excited state of oxyluciferin within luciferase, which gives luminescence calculated by the SAC−CI method that is close to the experimental value. Coulombic interactions with neighboring residues, in particular Arg218 and the phosphate group of AMP, play important roles in the color-tuning mechanism. Transformation to the enol form is energetically unfa...
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excited and ionized states of free base porphin studied by the symmetry adapted Cluster Configuration interaction sac ci method
Journal of Chemical Physics, 1996Co-Authors: Hiroshi Nakatsuji, Junya Hasegawa, Masahiko HadaAbstract:The SAC(symmetry adapted Cluster)/SAC‐CI method is applied to the calculations of the ground, excited, and ionized states of the free base porphin. The electronic spectrum of porphin is well reproduced and new assignments for the B (Soret), N, L, and M bands are proposed. The present result shows that the four‐orbital model is strongly perturbed for the B and N bands by the excitations from the lower 4b1u MO and that the σ electron correlations are important for the description of the excited states. The absorption peaks in the ionization spectrum are assigned and the reorganization effect is found to be large especially for the n and σ electron ionizations.