In this paper, we report the stability of the Li(HF) 3 molecular anion calculated at the MP2/631++G** and CCSD(T)/6-31++G** level of theory. Five possible conformers of Li(HF) 3 molecular anions have been determined employing ab initio MP2 method with 6-31++G** basis set. The most stable conformer of five Li(HF) 3 anions is in a cyclic ring structure Li(HF) 3 (1). From our calculations we show ...

An accurate set of benchmark rotational g tensors and magnetizabilities are calculated using coupled-cluster singles-doubles (CCSD) theory and coupled-cluster single-doubles-perturbative-triples [CCSD(T)] theory, in a variety of basis sets consisting of (rotational) London atomic orbitals. The accuracy of the results obtained is established for the rotational g tensors by careful comparison wit...

Different quantum chemical approaches to the ground state correlation energy per unit cell of infinite poly(para-phenylene) (PPP) chains are presented. PPP is an organic polymer with interesting optical properties, due to its conjugated, aromatic pi system. The inclusion of correlation effects is crucial for a sound quantum chemical description of such a system. The correlation calculations wer...

The regulation of the electronic properties of organic molecules induced by polynuclear superhalogens is theoretically explored here for sixteen composite structures. It is clearly indicated by the higher vertical electron detachment energy (VDE) that polynuclear superhalogens are more effective in regulating the electronic properties than mononuclear structures. However, this enhanced regulati...

This work presents the visual and quantitative comparison of Density Functional Theory (DFT) exchange-correlation energy xc E functionals with Coupled Cluster with Single and Double excitations (CCSD) calculations (and experiment where possible). The xc E functional is an approximate term which is a component of the total energy of a molecule. This comparison is based on visualizing the differe...

We report the implementation of the spin-conserving and spin-flipping variants of the equation-of-motion (EOM) coupled-cluster (CC) model, which includes single and double excitations in the CC part and single, double, and triple excitations in the EOM part, i.e., EOM-CC(2,3) [Hirata, Nooijen, Bartlett, Chem. Phys. Lett. 326, 255 (2000)] for closed- and open-shell references. Inclusion of tripl...

The low temperature spectra of the detectable species methyl hydroperoxide (CH3OOH) and three sulfur analogs, the two isomers of methanesulfenic acid (CH3SOH and CH3OSH) and the methyl hydrogen disulfide (CH3SSH), are predicted from highly correlated ab initio methods (CCSD(T) and CCSD(T)-F12). Rotational parameters, anharmonic frequencies, torsional energy barriers, torsional energy levels, an...

The action of fluoroacetate as a broad-spectrum mammalian pesticide depends on the 'lethal synthesis' of fluorocitrate by citrate synthase, through a subtle enantioselective enolization of fluoroacetyl-coenzyme A. In this work, we demonstrate how a projection-based embedding method can be applied to calculate coupled cluster (CCSD(T)) reaction profiles from quantum mechanics/molecular mechanics...

We present a study of excitation energies in solution at the equation of motion coupled cluster singles and doubles (EOM-CCSD) level of theory. The solvent effect is introduced with a state specific polarizable continuum model (PCM), where the solute-solvent interaction is specific for the state of interest. Three definitions of the excited state one-particle density matrix (1PDM) are tested in...

Probiotic foods and supplements have been shown to offer multiple potential health benefits consumers. Dried probiotic cultures are increasingly used by the food industry because they easily handled, transported, stored, in different applications. However, drying technologies often expose cells extreme environmental conditions that reduces cell viability. Hence, this study aimed evaluate effect...