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The charge-transfer (CT) excited state of FHCl (F+H–Cl−), generated by the photodetachment of an electron from its precursor anion (FHCl−) by a photon energy of ∼9.5 eV, is a realistic prototype of two bidirectional-coupled reaction pathways, namely the proton-transfer (PT) and electron-transfer (ET) channels, that produce F + HCl and FH + Cl combinations, respectively. The early-time dynamics of the CT was studied via the time-dependent propagations of nuclear wave packets comprising three nonadiabatically coupled electronic states defined within a three-dimensional space. The detailed analyses of the early-time dynamics revealed an interesting phenomenon in which the onset of PT was ∼80 fs earlier than that of ET, indicating that PT dominated ET in this case. A more significant finding was that the proper adjustment of the electronic-charge distribution for the onset of ET was obtained ∼80 fs after the onset of PT; this adjustment was mediated by the initial movement of the H atom, i.e., the F–H vibration mode. To avail experimental observables, the branching ratio, χ = PT/(PT + ET), and absorption spectrum generating the neutral FHCl molecule from its precursor anion were also simulated. The results further demonstrated the dependences of the χs and spectrum on the change in the initial vibration level of the precursor anion, as well as the isotopic substitution of the connecting H atom with deuterium, tritium, and muonium. [ABSTRACT FROM AUTHOR]

A charge-transfer (CT) excited state of NH3Cl, generated by photo-detachment of an electron from the anionic NH3Cl− precursor, can be represented as H2N+–H–Cl− and proceeds to two chemical reactions: one reaction generating NH2 and HCl resulting from a proton transfer (PT) and the other reaction producing NH3 and a Cl atom resulting from an electron transfer (ET); both are coupled to form a typical proton-coupled electron transfer (PCET) process. The early time dynamics of this CT were studied using time-dependent wavepacket propagation on three nonadiabatically coupled electronic states in a reduced three-dimensional space. The electronic states were treated using the XMS-CASPT2/aug-cc-pVTZ ab initio methodology. The population dynamics of the three coupled electronic states were analyzed in detail to reveal the initial stage of the PCET process up to ∼100 fs, while the branching ratio, χ = PT/(ET+PT), was determined after wavepacket propagations of up to 2000 fs. Another main result is the dependence of χ on the vibration levels of the initial precursor anion and the isotope substitution of the connecting H atom with deuterium and tritium. Our study reveals the detailed microscopic features of the PCET process embedded in the CT state of the NH3Cl complex and certain systematic dependences of the branching ratio χ on the above factors. [ABSTRACT FROM AUTHOR]

Becke's three-parameter density-functional theory was used to calculate the vibrational spectra of positive, neutral, and negative species of BCl2 and AlCl2. The negatively charged BCl2 and AlCl2 are shown to be stable in both singlet and triplet states with electron diffinities of 1.4 eV/0.25 eV and 2.37 eV/0.46 eV, respectively. The photoelectron spectra for the singlet and triplet states of BCl2- were observed to be very similar to AlCl2- analogs.

The photodissociation dynamics of methylamines (CH3NH2 and CD3ND2) on the first electronically excited state has been investigated using the velocity map ion imaging technique probing the H or D fragment. Two distinct velocity components are found in the H(D) translational energy distribution, implying the existence of two different reaction pathways for the bond dissociation. The high H(D) velocity component with the small internal energy of the radical fragment is ascribed to the N–H(D) fragmentation via the coupling of S1 to the upper-lying S2 repulsive potential energy surface along the N–H(D) bond elongation axis. Dissociation on the ground S0 state prepared via the nonadiabatic dynamics at the conical intersection should be responsible for the slow H(D) fragment. Several S1 vibronic states of methylamines including the zero-point level and nν9 states (n=1, 2, or 3) are exclusively chosen in order to explore the effect of the initial quantum content on the chemical reaction dynamics. The branching ratio of the fast and slow components is found to be sensitive to the initial vibronic state for the N–H bond dissociation of CH3NH2, whereas it is little affected in the N–D dissociation event of CD3ND2. The fast component is found to be more dominant in the translational distribution of D from CD3ND2 than it is in that of H from CH3NH2. The experimental result is discussed with a plausible mechanism of the conical intersection dynamics. [ABSTRACT FROM AUTHOR]

The low-lying electronic states of Ag[sub 3][sup -]([sup 1]Σ[sub g][sup +],[sup 3]B[sub 2]), Ag[sub 3]([sup 2]B[sub 2],[sup 2]A[sub 1],[sup 2]B[sub 1],[sup 4]B[sub 2],[sup 2]Σ[sub u][sup +],1 [sup 2]Σ[sub g][sup +],2 [sup 2]Σ[sub g][sup +],[sup 2]Π[sub u],[sup 4]Σ[sub u][sup +]), and Ag[sub 3][sup +]([sup 1]A[sub 1],[sup 1]Σ[sub g][sup +],[sup 3]Σ[sub u][sup +],[sup 3]A[sub 1]) are studied by ab initio calculations with the Stuttgart effective core potentials and corresponding (8s7p6d)/[6s5p3d] and (8s7p5d3f )/[6s5p3d3f] basis sets. The geometries, vibrational frequencies, and energetic splittings are obtained by the coupled-cluster method including singles and doubles (CCSD) and those including up to the noniterative triples [CCSD(T)] correlation methods with additional frozen core molecular orbitals corresponding to 4s and 4p orbitals. The results for well-studied states (Ag[sub 3][sup -] [sup 1]Σ[sub g][sup +];Ag[sub 3] [sup 2]B[sub 2],[sup 2]A[sub 1],[sup 2]Σ[sub u][sup +];Ag[sub 3][sup +] [sup 1]A[sub 1]) are in good agreement with previous experimental results, and therefore our results for other newly studied states are expected to be reliable. The vertical detachment energies of Ag[sub 3][sup -] are obtained by the electron excitation equation-of-motion coupled-cluster (EE-EOM-CCSD) method and the average deviation from the experimental results is small without any scaling correction of the obtained values. The effect of the f-functions in the basis sets and the noniterative triples in the CCSD(T) method is discussed; the bond lengths are reduced significantly and the vertical detachment energies and ionization potentials are in much better agreement with experiment. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The electron diffraction patterns of s-tetrazine in specific electronic and vibrational states are calculated. The differences in diffraction patterns of isoenergetic vibrational states provide an opportunity for observing the flow of vibrational energy through the phase space by time-dependent three-dimensional mapping.

All-electron relativistic self-consistent-field (RSCF) method based upon Dirac–Coulomb Hamiltonian is extended to include the magnetic part of the Breit interaction term in the SCF cycle. The explicit form of the Fock matrix for the magnetic part is derived and simplified within the restricted open-shell scheme. The effects of the magnetic part of the Breit term on spin–orbit splittings and dipole moments are investigated for 2Π states of diatomic hydrides AH (A=Be,B,C,N,O,F,Mg,Al,Si,P,S). Calculated spin–orbit splittings are improved significantly by the inclusion of the magnetic part and approach the experimental values to within 10 cm-1 even for the second-row diatomic hydrides. The magnitude of the effect of the magnetic part is similar for the molecules composed of atoms in the same group regardless of the nuclear charge implying that the magnetic part and probably the whole Breit term become less important for molecules with large spin–orbit interactions. With the present RSCF method, the effects of magnetic term on properties can be estimated from expectation values. The effects of the magnetic term on dipole moments of 2Π states of AH molecules are quite small. [ABSTRACT FROM AUTHOR]

Examines the low-lying electronic states of Al[sub 3] and Al[sup -][sub 3] through coupled-cluster methods. Calculation of geometries and harmonic frequencies by coupled-cluster single double triple correlation method; Analysis of processes of ionizations and vibronic transitions; Details on anticipated features of other electronic excitations.

Reports on the systematic study of the magnitude and trends of the effects of frozen molecular orbitals in coupled-cluster and many-body perturbation theory methods. Theoretical considerations and implementations; Effects of core correlation on geometry and vibrational frequencies.

Describes the structures, vibrational frequencies, ionization potentials, electron affinities and excited states of the boron trichloride plasma. Calculation of the excited, electron attached and ionized states by employing the equation-of-motion coupled cluster method; Features of the potential energy surfaces of excited states of boron trichloride.

ABSTRACT We present a fully transparent nonvolatile resistive polymer memory device based on an anthracene-containing partially aliphatic polyimide along with indium tin oxide (ITO) top and bottom electrodes. High transmittance of over 90% in the wavelength range of 400 to 800 nm is accomplished with an ITO/polyimide/ITO/glass device. The device shows unipolar write-once-read-many times (WORM) memory behavior with an ON/OFF current ratio of ∼2 × 103, and the ratio remained without any significant degradation for over 104 s. The memory behavior of the device is considered to be governed by trap-controlled space-charge limited conduction (SCLC) and local filament formation. Based on molecular simulation of the polyimide, the location of energy states is different from that in the conventional charge transfer (CT) mechanism. Despite the relatively low ON/OFF current ratio, our results can give insight into the development of fully transparent memory device. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 918-925 [ABSTRACT FROM AUTHOR]