1,721,253 research outputs found
Counterpoise Corrections to the Evaluation of the Bimolecular Interaction Energy Components. On the decoupling of the Emix term
No full textNonequilibrium solvation theory for the polarizable continuum model: a new formulation at the SCF level with application to the case of the frequency-dependent linear electric response function.
No full textNonempirical investigations on the azomethine group. 1. The effect of the conjugation with a phenyl ring. A comparison of the electronic structure of the ground and lowest excited states in benzaldimine and N- phenylformaldimine
No full textThe possibility of differential effects due to conjugation with a phenyl ring when linked either to the C or N end of the
azomethine group is investigated by means of ab initio calculations on the ground and lowest excited states of benzaldimine, N-phenylformaldimine, and the parent compound methylenimine. For the description of the excited states, the electron-hole potential method by Morokuma and Iwata has been adopted. Population analysis shows that the ability of the azomethine group to accept or to donate electrons in a given state is practically the same in molecules 1 and 2. A parallel analysis of the electrostatic molecular potential confirms the results of the papulation analysis and in addition shows differences in reactivity between the two molecules in a given state and among the various states in each molecule
Remarks on the use of the apparent surface charges (ASC) methods in solvation problems: iterative versus matrix-inversion procedures and renormalization of the apparent charges.
No full textAnalytical derivatives for molecular solutes. II. Hartree-Fock energy first derivatives with respect to nuclear coordinates.
No full textThe time-dependent variational principle for non-linear Hamiltonians and its application to molecules in liquid phase.
No full textAnalytical derivatives for molecular solutes. I. Hartree-Fock energy first derivatives with respect to external parameters in the polarizable continuum model.
No full text
Electronic excitation energies of molecules in solution within continuum solvation models: Investigating the discrepancy between state specific and linear response methods
No full textIn a recent article (R. Cammi, S. Corni, B. Mennucci, and J. Tomasi, J. Chem. Phys. 122, 104513,2005), we demonstrated that the state-specific (SS) and the linear-response (LR) approaches, two different ways to calculate solute excitation energies in the framework of quantum-mechanical continuum models of solvation, give different excitation energy expressions. In particular, they differ in the terms related to the electronic response of the solvent. In the present work, we further investigate this difference by comparing the excitation energy expressions of SS and LR with those obtained through a simple model for solute-solvent systems that bypasses one of the basic assumptions of continuum solvation models, i.e., the use of a single Hartree product of a solute and a solvent wave function to describe the total solute-solvent wave function. In particular, we consider the total solute-solvent wave function as a linear combination of the four products of two solute states and two solvent electronic states. To maximize the comparability with quantum-mechanical continuum model the resulting excitation energy expression is recast in terms of response functions of the solvent and quantities proper for the solvated molecule. The comparison of the presented expressions with the LR and SS ones enlightens the physical meaning of the terms included or neglected by these approaches and shows that SS agrees with the results of the four-level model, while LR includes a term classified as dispersion in previous treatments and neglects another related to electrostatic. A discussion on the possible origin of the LR flaw is finally given
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