Brueckner doubles coupled cluster method with the polarizable continuum model of solvation

Abstract

Articles you may be interested inAnalytic gradient for second order Møller-Plesset perturbation theory with the polarizable continuum model based on the fragment molecular orbital method J. Chem. Phys. 136, 204112 (2012) We present the theory and implementation for computing the (free) energy and its analytical gradients with the Brueckner doubles (BD) coupled cluster method in solution, in combination with the polarizable continuum model of solvation (PCM). The complete model, called PTED, and an efficient approximation, called PTE, are introduced and tested with numerical examples. Implementation details are also discussed. A comparison with the coupled-cluster singles and doubles CCSD-PCM-PTED and CCSD-PCM-PTE schemes, which use Hartree-Fock (HF) orbitals, is presented. The results show that the two PTED approaches are mostly equivalent, while BD-PCM-PTE is shown to be superior to the corresponding CCSD scheme when the HF reference wave function is unstable. The BD-PCM-PTE scheme, whose computational cost is equivalent to gas phase BD, is therefore a promising approach to study molecular systems with complicated electronic structure in solution.

A comparison between state-specific and linear-response formalisms for the calculation of vertical electronic transition energy in solution with the CCSD-PCM method

“…49 These radii were parameterized to reproduce values of solvation free energy computed with the B3LYP 50 hybrid functional and, in my experience, work well also for CC methods. 33,34,37,40,41,51 The nonequilibrium regime is used for all calculations. The augcc-pVDZ basis set 52 is used throughout, and all geometries are optimized in the corresponding medium at CCSD level.…”

“…Additionally, this allows the definition of approximations in the correlation solvation that greatly reduce the computational cost of the calculation. 14, 32-34, 37, 40 The SCF is decoupled from the CC part of the calculation as for gas phase CC (unless Brueckner orbitals are employed, 41 but this is not considered here) both for ground and excited states.…”

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].…”

Implementation of the CCSD-PCM linear response function for frequency dependent properties in solution: Application to polarizability and specific rotation

“…However, previous work done by Christiansen and Mikkelsen on a different solvation model called dielectric continuum (DC) should be mentioned. [12][13][14] The development of CCSD-PCM (with Hartree-Fock, HF, and Brueckner orbitals) 8,15 includes energy and analytic energy gradients, transition energies, and their analytic gradients in the equilibrium and non-equilibrium regimes in a statespecific (SS) formulation, 10,11 so that both ground and excited states potential energy surfaces can be explored and vertical transition energy computed both in absorption and in emission. Furthermore, a variety of approximate schemes have been proposed that reduce the computational cost to a level comparable to gas phase calculations.…”