High-level ab initio calculations employing the CCSD and CCSD(T) coupled cluster methods with a series of systematically convergent correlation-consistent basis sets have been performed to obtain accurate molecular geometry and energetic properties of the simplest S-nitrosothiol (RSNO), HSNO. The properties of the S-N bond, which are central to the physiological role of RSNOs in the storage and...

Ab initio all-electron molecular-orbital calculations are carried out to study the structures and relative stability of low-energy silicon clusters (Si(n),n = 12-20). Selected geometric isomers include those predicted by Ho et al. [Nature (London) 392, 582 (1998)] based on an unbiased search with tight-binding/genetic algorithm, as well as those found by Rata et al. [Phys. Rev. Lett. 85, 546 (2...

The mechanism of the self-reaction of HCO radicals is investigated by using high-level quantum-chemical methods including M05-2X, CCSD, CCSD(T) and CRCC(2,3). Next, the rate coefficients for several product channels as a function of pressure and temperature are computed by employing statistical rate theories. Four important product channels are predicted to be CO + CO + H2, HCOH + OH, cis-(HCO)...

Density functional theory (DFT) functionals for calculations of binding energies (BEs) the polyethylene (PE) chains cross-linked by selected metal atoms (M) are benchmarked against DLPNO–CCSD(T) and DLPNO–CCSD(T1) data. PEX-M-PEX complexes as compared with plain parallel PEX···PEX X = 3–9 carbon model species characterized a cooperative effect covalent C-M-C bonds interchain dispersion interact...

We report the first computations of circularly polarized luminescence (CPL) rotatory strengths at the equation-of-motion coupled cluster singles and doubles (EOM-CCSD) level of theory. Using a test set of eight chiral ketones, we compare both dipole and rotatory strengths for absorption (electronic circular dichroism) and emission to the results from time-dependent density-functional theory (TD...

Coupled cluster (CC) methods provide highly accurate predictions of molecular properties, but their high computational cost has precluded their routine application to large systems. Fortunately, recent computational developments in the ACES III program by the Bartlett group [the OED∕ERD atomic integral package, the super instruction processor, and the super instruction architecture language] pe...

The structures of SiGenSc0/− (n = 3, 4) clusters were investigated by a combination quantum chemical calculations, including the genetic algorithm (GA), Perdew-Burke-Ernzerhof PBE functional, and coupled- cluster calculations (CCSD(T)). geometrical structure, relative energy, harmonic vibrational frequency, adiabatic detachment energies reported. functional is in good agreement with CCSD(T) met...

Several levels of theory, including both Gaussian-based and plane wave density functional theory (DFT), second-order perturbation theory (MP2), and coupled cluster methods (CCSD(T)), are employed to study Au6 and Au8 clusters. All methods predict that the lowest energy isomer of Au6 is planar. For Au8, both DFT methods predict that the two lowest isomers are planar. In contrast, both MP2 and CC...

A nearly linear scaling implementation of coupled-cluster with singles and doubles excitations (CCSD) can be achieved by means the domain-based local pair natural orbital (DLPNO) method. The combination DLPNO-CCSD implicit solvation methods allows calculation accurate energies chemical properties solvated systems at an affordable computational cost. We have efficiently implemented different sch...