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

Abstract

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.

Electronic excitations in a dielectric continuum solvent with quantum Monte Carlo: Acrolein in water

“…(formally, corresponding to an infinitely large cavity) and the fastest response by a value of water refractive index of 1.468 while, for η = 1, we have no fast response. For comparison, we also report recent theoretical transition energies of the isolated acrolein molecule from the literature [17][18][19][20] together with the relevant experimental reference 43,44 corresponding to the photon energy at which the gas-phase acrolein displays the maximum absorption. If we consider our DMC vacuum transition energy for the n → π * transition, the energy is always within 0.1 eV of other calculated values in the literature and within 0.13 eV of the experimental value.…”

“…We choose this system because it has been widely studied, it shows a solvent effect in the UV absorption spectrum and, for the two aforementioned transitions, the effect of the solvent water is opposite. [17][18][19][20] The outline of the paper is as follows. In Sec.…”

Modeling Molecular Systems at Extreme Pressure by an Extension of the Polarizable Continuum Model (PCM) Based on the Symmetry-Adapted Cluster-Configuration Interaction (SAC–CI) Method: Confined Electronic Excited States of Furan as a Test Case

“…11 The SAC−CI is a wellestablished method for studying excited-state chemistry, and the PCM SAC/SAC−CI has been applied successfully to spectroscopy and photochemistry of various solvated systems. In this study, we extend the PCM SAC and PCM SAC−CI to the PCM-XP framework and develop the PCM-XP SAC and SAC−CI methods for considering the high-pressure effect on the ground and excited states at the correlated wave function level.…”

Molecular Response Functions for the Polarizable Continuum Model

“…The PCM model contains the largest variety of extensions for the calculation of the properties for the ground and excites states of molecular systems in solution [44][45][46][47][48][49] and these extensions have been accomplished at HF level and at various QM electron correlation methods [27,[50][51][52][53][54][55][56][57]. There are also version based on semi-empirical QM methods: we quote here only those based on ZINDO [58].…”