The polarizable embedding (PE) model is a fragment-based quantum-classical approach aimed at accurate inclusion of environment effects in quantum-mechanical response property calculations. The aim of this tutorial review is to give insight into the practical use of the PE model.Starting from a set of molecular structures and until you arrive at the final property, there are many crucial details to consider in order to obtain trustworthy results in an efficient manner. To lower the threshold for new users wanting to explore the use of the PE model, we describe and discuss important aspects related to its practical use. This includes directions on how to generate input files and how to run a calculation. K E Y W O R D S computational spectroscopy, molecular properties, polarizable embedding, QM/MM, response properties 1 | INTRODUCTION Hybrid quantum-classical approaches for modeling of chemical or biological systems have in recent years gained considerable interest. The reasonfor such popularity of these models relies, to a large degree, on their efficiency and the fact that such models enable calculations on systems of sizes that are otherwise impossible using pure quantum-mechanical methods. The dielectric continuum models belong to the simplest of the quantum-classical approaches, [1,2] and models like the polarizable continuum model [3,4] are today implemented in many of the available electronic-structure programs. In addition, such models are very easy to use: based on a predefined set of atomic radii and the dielectric constant of the solvent, the user can include solvation effects based only on a single calculation. Only one calculation is needed because the dielectric continuum models implicitly include sampling of solvent configurations. On the other hand, it is well-known that the dielectric continuum models possess several drawbacks, such as the inability to model the directionality of specific intermolecular interactions like hydrogen bonding or π-π stacking. Because of this, modeling of environment anisotropies, as found in, for example, protein matrices is lost.Another class of quantum-classical approaches consists of discrete models where the atomistic detail of the environment is kept, that is, models based on the concept of combined quantum mechanics and molecular mechanics (QM/MM). [5][6][7][8] Discrete models, compared to the dielectric continuum models, realistically describe the environment, but at an increased level of both complexity and computational requirements.Regarding the latter point, the increase in computational time is not linked to the discrete nature of the environment as such but rather that

The low-lying electronic states of ThF + , a possible candidate in the search for and  -violation, have been studied using high-level correlated relativistic ab initio multi-reference coupled-cluster and configuration interaction approaches. For the Δ 3 state component with Ω = 1 (electron electric dipole moment 'science state') we obtain an effective electric field of = E 35.2 eff − 1 ), challenging the state assignment from an earlier theoretical study on this species (Barker et al 2012 J. Chem. Phys. 136 104305).e 29 cm. This value is more than 16 times smaller than the most constraining upper bound from an atomic study [12]. Charged molecules offer an experimental advantage over neutral OPEN ACCESS RECEIVED

We present a study of mobility field and temperature dependence for C60 with Kinetic Monte Carlo simulations. We propose a new scheme to take into account polarization effects in organic materials through atomic induced dipoles on nearby molecules. This leads to an energy correction for the single site energies and to an external reorganization happening after each hopping. The inclusion of polarization allows us to obtain a good agreement with experiments for both mobility field and temperature dependence.

In this paper we present a study of the methodological aspects regarding calculations of optical properties for DNA systems in solution. Our computational approach will be built upon a fully polarizable QM/MM/Continuum model within a damped linear response theory framework. In this approach the environment is given a highly advanced description in terms of the electrostatic potential through the polarizable embedding model. Furthermore, bulk solvent effects are included in an efficient manner through a conductor-like screening model. With the aim of reducing the computational cost we develop a set of averaged partial charges and distributed isotropic dipole-dipole polarizabilities for DNA suitable for describing the classical region in ground-state and excited-state calculations. Calculations of the UV-spectrum of the 2-aminopurine optical probe embedded in a DNA double helical structure are presented. We show that inclusion of polarizabilities in the embedding potential stemming from the DNA double helix is of crucial importance, while the water cluster surrounding the DNA system is well represented using a continuum approach.