Accurate sets of benchmark nuclear-magnetic-resonance shielding constants and spin-rotation constants are calculated using coupled-cluster singles-doubles (CCSD) theory and coupled-cluster singles-doubles-perturbative-triples [CCSD(T)] theory, in a variety of basis sets consisting of (rotational) London atomic orbitals. The accuracy of the calculated coupled-cluster constants is established by ...

We investigate the magnitude and interplay of relativistic and electron correlation effects on the electric field gradient (EFG) at the position of Hg in linear and bent HgL(2) (L = CH(3), Cl, Br, I) and trigonal planar [HgCl(3)](-) compounds using four-component relativistic Dirac-Coulomb (DC) and non-relativistic (NR) calculations at the Hartree-Fock (HF), DFT, MP2 and coupled cluster (CC) le...

An implementation of gradient and energy calculations for configuration interaction variant of equation-of-motion coupled cluster with single and double substitutions for ionization potentials (EOM-IP-CCSD) is reported. The method (termed IP-CISD) treats the ground and excited doublet electronic states of an N-electron system as ionizing excitations from a closed-shell N+1-electron reference st...

In the aim of completing our previous efforts devoted to local and Rydberg transitions in organic compounds, we provide a series highly-accurate vertical transition energies for intramolecular charge-transfer occurring ($\pi$-conjugated) molecular compounds. To this end apply composite protocol consisting linear-response CCSDT excitation determined with Dunning's double-$\zeta$ basis set correc...

Systematic quantum chemical calculations have been performed to obtain precise estimates of the equilibrium and vibrationally averaged molecular structure and electric dipole moment of vinylacetylene (VA, 1-buten-3-yne). Anharmonic (cubic and semi-diagonal quartic) MP2/cc-pVTZ force fields in normal coordinates were computed to account for anharmonic vibrational effects, including zero-point co...

The intermolecular forces between anti–cancer molecules such as Cisplatin, Carboplatin, Oxaliplatin, Nedaplatin, Lobaplatin, Heptaplatin, Dicycloplatin, Eleutherobin, Epothilone B, Discodermolide and Taxol (Figures 1 and 2) and tumor multiple organs or tissues are of great importance in many areas of science including medicine, chemotherapy, pharmacology, medicinal chemistry, pharmaceutical che...

Complete basis set limit calculations are carried out for the fcc lattices of solid neon and argon, using secondto fourth-order Møller-Plesset theory, MP2–MP4, and coupled-cluster calculations, CCSD T , to describe electron correlation within a many-body expansion of the interaction potential up to third order. A correct description of the three-body Axilrod-Teller-Muto term for the solid state...

In this paper, correlated studies on a test set of 36 small molecules are carried out with both wavefunction (HF, MP2, CCSD) and density functional (LDA, KT3, cTPSS, cM06-L) methods. The effect correlation exotic response properties such as molecular electronic anapole susceptibilities is studied the performance various approximations benchmarked against CCSD and/or MP2. Atoms traditionally cla...

The projection-based quantum embedding method is applied to a comprehensive set of electronic states. We embed different variants equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) theory in density functional investigate electronically excited states valence, Rydberg, charge-transfer character, valence- core-ionised states, as well bound temporary radical anions. latter which ar...

Coupled-cluster theory with single and double excitations (CCSD) is a promising ab initio method for the electronic structure of three-dimensional metals, which second-order perturbation (MP2) diverges in thermodynamic limit. However, due to high cost poor convergence CCSD respect basis size, applying periodic systems often leads large set errors. In common "composite" method, MP2 used recover ...