MgH2分子的激发态研究

本文采用ＳＣＦ、ＭＣＳＣＦ、ＳＯＣＩ方法对ＭｇＨ＿２的基态和两个激发态进行了计算研究，预言了各态的平衡几何构型、总能量、偶极矩、电荷分布等性质，并首次报道了各态的振动频率。     

ZnNe低激发态的量子化学研究

用相对论赝势ＣＡＳＳＣＦ／ＣＩ方法,对ＺｎＮｅ的基态和低激发态进行了计算,得出了它们的电子结构,势能曲线及光谱常数。计算结果表明,ＺｎＮｅ的基态分子是范德华分子,它的几个低激发态分子中的主要作用力为范德华力,这些态的分子仍为范德华分子。     

超大孔Fe和V—Ti分子筛的合成

水热法合成了具有超大孔ＭＣＭ－４１分子筛结构的含Ｆｅ和Ｖ－Ｔｉ分子筛，通过ＸＲＤ，骨架ＩＲ，ＥＳＲ，＾２９ＳｉＭＡＳ ＮＭＲ，紫外漫反射等测试表征证实，Ｆｅ原子在ＦｅＭＣＭ－４１分子筛骨架上，Ｖ和Ｔｉ同是进入Ｖ－ＴｉＭＣＭ－４１分子筛骨架。     

SCANNED LASER SPOT PHOTOCURENT RESPONSE STUDIES OF FERROCENE DERIVATIVE LB FILMS MODIFED CdSe THIN F

ＳＣＡＮＮＥＤ　ＬＡＳＥＲ　ＳＰＯＴ　ＰＨＯＴＯＣＵＲＥＮＴ　ＲＥＳＰＯＮＳＥ　ＳＴＵＤＩＥＳ　ＯＦ　ＦＥＲＲＯＣＥＮＥ　ＤＥＲＩＶＡＴＩＶＥ　ＬＢ　ＦＩＬＭＳ　ＭＯＤＩＦＥＤ　ＣｄＳｅ　ＴＨＩＮ　ＦＩＬＭ　ＥＬＥＣＴＲＯＤＥＳＳＣＡＮＮＥＤＬＡＳＥ...     

C60的激发态光谱S1→Sn,T1→Tn与反饱和吸收

用ＩＮＤＯ／ＣＴ方法研究了Ｃ６０分子的电子结构及基态和激发态光谱（Ｓ０→Ｓｎ，Ｓ１→Ｓｎ，Ｔ１→Ｔｎ），激发态分子动态学和反饱和吸收的微观机制，用动态模型解速率方程，实现反饱和吸收的必要条件是激发态对激光的吸收截面，在波长５３２ｎｍ的激光作用下，Ｃ６０满足该条件，故Ｃ６０呈现反饱合吸收特征，理论分析与实验结果一致。     

CYCLIC VOLTAMMETRIC INVESTIGATION OF THE MICELLAR PHASE OF SODIUM DODECYL SULFATE IN AQUEOUS SOLUTIONS

ＣＹＣＬＩＣＶＯＬＴＡＭＭＥＴＲＩＣＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦＴＨＥＭＩＣＥＬＬＡＲＰＨＡＳＥＯＦＳＯＤＩＵＭＤＯＤＥＣＹＬＳＵＬＦＡＴＥＩＮＡＱＵＥＯＵＳＳＯＬＵＴＩＯＮＳ￥ＣｈｕｎＳｈｅｎｇＭＯ；ＺｈｅｎＺｈｏｎｇＨＵＡＮＧ；ＭｉｎｇＨｕａＺ...     

TOTAL SYNTHESIS OF CURVULARIN－TYPE MACROLIDES 12－OXOCURVULARIN AND CITREOFURAN

ＴＯＴＡＬ　ＳＹＮＴＨＥＳＩＳ　ＯＦ　ＣＵＲＶＵＬＡＲＩＮ－ＴＹＰＥ　ＭＡＣＲＯＬＩＤＥＳ　１２－ＯＸＯＣＵＲＶＵＬＡＲＩＮ　ＡＮＤ　ＣＩＴＲＥＯＦＵＲＡＮＴＯＴＡＬＳＹＮＴＨＥＳＩＳＯＦＣＵＲＶＵＬＡＲＩＮ－ＴＹＰＥＭＡＣＲＯＬＩＤＥＳ１２－ＯＸＯ...     

A QUANTUM CHEMICAL INVESTIGATION OF ACTIVITY ORDER OF COORDINATION CATALYSIS OF TRANSITION METALS（Ⅲ） ……ACTIVATION OF MOLECULAR OXYGEN

ＡＱＵＡＮＴＵＭＣＨＥＭＩＣＡＬＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦＡＣＴＩＶＩＴＹＯＲＤＥＲＯＦＣＯＯＲＤＩＮＡＴＩＯＮＣＡＴＡＬＹＳＩＳＯＦＴＲＡＮＳＩＴＩＯＮＭＥＴＡＬＳ（Ⅲ）……ＡＣＴＩＶＡＴＩＯＮＯＦＭＯＬＥＣＵＬＡＲＯＸＹＧＥＮ￥ＹｕａｎＱｉｎ...     

SYNTHESIS,STRUCTURE AND LUMINESCENCE PROPERTIES OF K_2VOF_5 AND K_3VO_2F_4

ＳＹＮＴＨＥＳＩＳ，　ＳＴＲＵＣＴＵＲＥ　ＡＮＤ　ＬＵＭＩＮＥＳＣＥＮＣＥ　ＰＲＯＰＥＲＴＩＥＳ　ＯＦ　Ｋ＿２ＶＯＦ＿５　ＡＮＤ　Ｋ＿３ＶＯ＿２Ｆ＿４ＳＹＮＴＨＥＳＩＳ，ＳＴＲＵＣＴＵＲＥＡＮＤＬＵＭＩＮＥＳＣＥＮＣＥＰＲＯＰＥＲＴＩＥＳＯＦＫ＿２Ｖ...     

A SIMPLE，EFFICIENTPROCEDURE FOR TIIE SYNTIIESIS OF SOME AMINO ACID LINKED URREIDO PHOSPHORAMIDATEDERIVATIVES

ＡＳＩＭＰＬＥ，ＥＦＦＩＣＩＥＮＴＰＲＯＣＥＤＵＲＥＦＯＲＴＩＩＥＳＹＮＩＩＥＳＩＳＯＦＳＯＭＥＡＭＩＮＯＡＣＩＤＬＩＮＫＥＤＵＲＲＥＩＤＯＰＨＯＳＰＨＯＲＡＭＩＤＡＴＥＤＥＲＩＶＡＴＩＶＥＳＲｕＹｕＣＨＥＮａｎｄＪｉａＺＨＯＵ．（Ｉｎｓｔｉｔｕｔｅ...     

Möller-plesset perturbation theory for excited states of molecules

We consider the criteria that should be met by the perturbation theory for excited states to preserve the advantages of the Möller-Plesset version for the ground state. A few zero-approximation Hamiltonians are proposed and discussed. Expressions for the first-order corrections to the wave function and for the second-order corrections to the energy of excited states are obtained. The expressions are consistent with the conditions of orthogonality of states with the same symmetry. It is shown that the perturbation theory for excited states proposed in this work is identical to the Möller-Plesset perturbation theory for the ground state.     

Multi-configuration electron-hole potential method for excited states

The recently proposed electron-hole potential (EHP) method for excited states is extended to the multi-configurational case. The variation equation is solved using the quadratic convergence method. The EHP methods are shown to be approximations to the complete singly excited configuration interaction (CSECI) in the variational sense. Extended Brillouin theorems are proved for the EHP methods. The excitation energies and wave functions obtained by one and two configurational EHP methods agree well with those of the CSECI method. The EHP methods have clear advantage in the computer time requirement over the CI method and are especially suited for a calculation of approximate excited states of large molecules. The EHP methods are applicable to excited states which belong to the same irreducible representation as the ground state.     

An ab initio multireference perturbation theory study on the manganese dimer

The potential energy curves of the ground state and of some excited states of the manganese dimer have been calculated over a wide range of internuclear distances using the second order n-electron valence state perturbation theory applied to a complete active space self-consistent field reference wave function. The ground state of Mn(2), for which also the third order NEVPT has been used, is calculated to be a singlet belonging to the Sigma(g) (+) symmetry, characterized by a large equilibrium internuclear distance R(e) of 3.7-3.8 A, by a low dissociation energy D(e) of 0.07-0.08 eV, and by a small harmonic frequency omega(e) of 43 cm(-1). The experimental evidence that Mn(2) is a van der Waals molecule is thus confirmed. Among the excited states, (11)Pi(u), which is usually indicated as the ground state by density functional theory studies, appears as a low-lying state with R(e)=2.50 A, D(e)=1.35 eV, and omega(e)=246 cm(-1).     

Optimized Jastrow-Slater wave functions for ground and excited states: application to the lowest states of ethene

A quantum Monte Carlo method is presented for determining multideterminantal Jastrow-Slater wave functions for which the energy is stationary with respect to the simultaneous optimization of orbitals and configuration interaction coefficients. The approach is within the framework of the so-called energy fluctuation potential method which minimizes the energy in an iterative fashion based on Monte Carlo sampling and a fitting of the local energy fluctuations. The optimization of the orbitals is combined with the optimization of the configuration interaction coefficients through the use of additional single excitations to a set of external orbitals. A new set of orbitals is then obtained from the natural orbitals of this enlarged configuration interaction expansion. For excited states, the approach is extended to treat the average of several states within the same irreducible representation of the pointgroup of the molecule. The relationship of our optimization method with the stochastic reconfiguration technique by Sorella et al. is examined. Finally, the performance of our approach is illustrated with the lowest states of ethene, in particular with the difficult case of the 1(1)B(1u) state.     

Theoretical investigation of excited states of C(3)

In this work, we present ab initio calculations for the potential energy surfaces of C(3) in different electronic configurations, including the singlet ground state [X (1)Sigma(g) (+),((1)A(1))], the triplet ground state [a (3)Pi(u),((3)B(1), (3)A(1))], and some higher excited states. The geometries studied include triangular shapes with two identical bond lengths, but different bond angles between them. For the singlet and triplet ground states in the linear geometry, the total energies resulting from the mixed density functional--Hartree-Fock and quadratic configuration interaction methods reproduce the experimental values, i.e., the triplet occurs 2.1 eV above the singlet. In the geometry of an equilateral triangle, we find a low-lying triplet state with an energy of only 0.8 eV above the energy of the singlet in the linear configuration, so that the triangular geometry yields the lowest excited state of C(3). For the higher excited states up to about 8 eV above the ground state, we apply time-dependent density functional theory. Even though the systematic error produced by this approach is of the order of 0.4 eV, the results give different prospective to insight into the potential energy landscape for higher excitation energies.     

Relativistic DMRG calculations on the curve crossing of cesium hydride

Over the past few years, it has been shown in various studies on small molecules with only a few electrons that the density-matrix renormalization group (DMRG) method converges to results close to the full configuration-interaction limit for the total electronic energy. In order to test the capabilities of the method for molecules with complex electronic structures, we performed a study on the potential-energy curves of the ground state and the first excited state of 1sigma+ symmetry of the cesium hydride molecule. For cesium relativistic effects cannot be neglected, therefore we have used the generalized arbitrary-order Douglas-Kroll-Hess protocol up to tenth order, which allows for a complete decoupling of the Dirac Hamiltonian. Scalar-relativistic effects are thus fully incorporated in the calculations. The potential curves of the cesium hydride molecule feature an avoided crossing between the ground state and the first excited state, which is shown to be very well described by the DMRG method. Compared to multireference configuration-interaction results, the potential curves hardly differ in shape, for both the ground state and the excited state, but the total energies from the DMRG calculations are in general consistently lower. However, the DMRG energies are as accurate as corresponding coupled cluster energies at the equilibrium distance, but convergence to the full configuration-interaction limit is not achieved.     

The fuzzy D<Subscript>6h</Subscript>-symmetries of azines molecules and their molecular orbitals

Based on our previous study on the elementary characterization of fuzzy symmetry, we inquire into the fuzzy symmetries of some simple linear and plane molecules. These systems belong to point groups that include the identity and twofold symmetry elements, but not include higher multi-fold symmetry ones, and their molecular orbitals (MOs) only belong to one-dimension irreducible representations. In this paper, we take the azines as a typical model to examine the fuzzy symmetry in relation to the D_6h point group. As this group includes multi-fold symmetry elements such as a sixfold rotation axis, some of the MOs may belong to two-dimensional irreducible representations. We inquire into the fuzzy symmetry of these molecules and their MOs in terms of membership functions, representation components and correlation diagrams. In addition to these neutral closed shell molecules, pyridine hydride radical, anion, and cation are also analyzed.     

Density functional theory study of 1,2‐dioxetanone decomposition in condensed phase

The decomposition of 1,2‐dioxetanone into a CO₂ molecule and into an excited state formaldehyde molecule was studied in condensed phase, using a density functional theory approach. Singlet and triplet ground and excited states were all included in the calculations. The calculations revealed a novel mechanism for the chemiluminescence of this compound. The triplet excitation can be explained by two intersystem crossings (ISCs) with the ground state, while the singlet excitation can be accounted by an ISC with the triplet state. The experimentally verified small excitation yield can then be explained by the presence of an energy barrier present in the potential energy surface of the triplet excited state, which will govern both triplet and singlet excitation. It was also found that the triplet ground state interacts with both the triplet excited and singlet ground states. A MPWB1K/mPWKCIS approach provided results in agreement with the existent literature. © 2012 Wiley Periodicals, Inc.     

Complete TDA and RPA Calculations on the Electronic Transitions of Fullerene‐C60 in the CNDO/S and INDO/S Approximations*

Complete single‐excitation mixing calculations on the electronic transitions of the icosahedral C₆₀ molecule have been carried out with the Tamm–Dancoff approximation (TDA) and random‐phase approximation (RPA) schemes in the CNDO/S and INDO/S approximations. The complete space of 14,400 (1p–1h) pairs is partitioned into subspaces classified according to the irreducible representations of the Ih group. For this purpose, matrix representations of the group generators are obtained on a fixed set of basis functions and are used to construct the projection operators. Degenerate molecular orbitals in each energy level are symmetry‐adapted to these projection operators. Degenerate (1p–1h) pairs or singly excited configuration wave functions are similarly symmetrized. In addition, the Clebsch–Gordan coefficients are obtained and listed in an Appendix. The TDA and RPA equations are then solved for each irreducible representation separately. Both schemes with the projection operators and with the Clebsch–Gordan coefficients gave the same results as expected, indicating that the calculations were correctly done. The transition energies from the ground state 1¹A_g to low‐lying singlet and triplet excited states and the oscillator strengths for the allowed transitions (n¹T_1u–1¹A_g) are given in tables. A proper way to normalize is discussed for the eigenvectors of the RPA‐type matrix equation. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001