Cooperative effects in two-dimensional cyclic networks containing intermolecular three-centered hydrogen bonding interactions of the type H1...A...H2 are investigated by means of ab intio molecular orbital and density functional theory calculations. Ring-like clusters consisting of three and up to nine monomers of the cis-cis isomer of carbonic acid H2CO3 are used as basic models, where each un...

the effect of interactions of various ia and iia cations with two positions of the adenine-thymine (a−t) and guanine-cytosine (g−c) base pairs on the geometries and individual hydrogen bond (hb) energies have been investigated by using the atoms in molecules (aim) method at the b3lyp/6-311++g(d,p) level of theory. the cations that possess higher charge/radius (q/rad) ratio make higher changes o...

The vibrational frequencies of N-benzoyl glycine in the ground state have been calculated using density functional method (B3LYP) by using 6-311++G(d,p) basis set. Theoretical vibrational spectra have been interpreted by means of potential energy distribution (PEDs) using MOLVIB program. The equilibrium geometry and the thermodynamic functions of the title compound have been performed at HF/6-3...

In this research at the first, captopril drug (CA) and its fullerene connected form (FCA) wereoptimized. Natural Bond Orbital (NBO) calculations for these compounds were carried out at theB3LYP/6-31G quantum chemistry level, in the gas phase and the liquid phase. These calculations canbe performed at different accuracy levels depending on the aim of the theoretical study [1]. Forinstance, Densi...

The hybrid density functional theory (B3LYP) and ab initio molecular orbital (HF) based methods and Natural Bond Orbital (NBO) interpretation were used to analyze the conformational behaviors of 2,5,5-trimethyl-1,3,2-dioxaphosphinane 2-selenide (compound 1), 2,5,5-trimethyl-1,3,2-dithiaphosphinane 2-selenide (compound 2) and 2,5,5-trimethyl-1,3,2-diselena phosp...

in this research at the first, captopril drug (ca) and its fullerene connected form (fca) wereoptimized. natural bond orbital (nbo) calculations for these compounds were carried out at theb3lyp/6-31g quantum chemistry level, in the gas phase and the liquid phase. these calculations canbe performed at different accuracy levels depending on the aim of the theoretical study [1]. forinstance, densi...

Generalized valence bond plus configuration interaction calculations have been carried out on the monopositive diatomic metal hydride ions of the second transition-metal series (YH+-CdH+, including SrH'). We analyze the trends in bond energies, equilibrium geometries, vibrational frequencies, and metal orbital hybridizations. The trends in these quantities can be understood in terms of (1) the ...

Density functional theory dispersion corrected (DFT-D3)calculations and molecular dynamic (MD) simulation were applied to investigate the sensing ability of four types of receptors (RCs) composed of the ortho-phenylenediamine based bis-ureas for selective complexation with the anions such as Cl–, Br–, OAC–, PhCO2–, H2PO4– and HSO4– in the gas phase and DMSO. On the basis of the data obtained fr...