An approximate formula is derived and implemented in the general effective fragment potential (EFP2) method to model the intermolecular charge transfer interaction. This formula is based on second order intermolecular perturbation theory and utilizes canonical molecular orbitals and Fock matrices obtained with preparative self-consistent field calculations. It predicts charge transfer energies ...

The thermodynamics of self-assembling systems are discussed in terms of the chemical interactions and the intermolecular forces between species. It is clear that there are both theoretical and practical limitations on the dimensions and the structural regularity of these systems. These considerations are made with reference to the microphase separation that occurs in block copolymer (BCP) syste...

in this study, functionalized β-cyclodextrin (β-cd) by aldehyde group was investigated as an oxidase enzyme mimic for the amino phenol oxidation. all calculations were performed by gaussian 09 package using two layers oniom method at the oniom (mpw1pw91/6-311++g(d,p)/uff) level. in the first step, h2o2 is encapsulated in the hydrophobic cavity. in the second step, h2o2 molecule oxidized the ald...

a quantum chemical investigation was carried out to study the properties of intermolecular f•••f, br•••br and br•••o interactions in crystalline 1-bromo-2,3,5,6-tetrafluoro-nitrobenzene (bfnb). this system was selected to mimic the halogen-halogen as well as halogen bonding interactions found within crystal structures as well as within biological systems. we found that fluorine atoms have weak ...

We discuss theoretically the geometric and electronic structure properties of the thiazolidinedione derivative A and its hydrogen-bonded complex in dimethylformamide (DMF) solution in the S0 and S1 states. To gain insight into the photoinduced coupled excited-state proton transfer (ESPT) and twisted intramolecular charge transfer (TICT) associated with intermolecular hydrogen bonding, the poten...

Accurate representation of the molecular electrostatic potential, which is often expanded in distributed multipole moments, is crucial for an efficient evaluation of intermolecular interactions. Here we introduce a machine learning model for multipole coefficients of atom types H, C, O, N, S, F, and Cl in any molecular conformation. The model is trained on quantum-chemical results for atoms in ...

The rotational spectrum of the van der Waals complex CH4-CO has been measured with the intracavity OROTRON jet spectrometer in the frequency range of 110-145 GHz. Newly observed and assigned transitions belong to the K = 2-1 subband correlating with the rotationless jCH4 = 0 ground state and the K = 2-1 and K = 0-1 subbands correlating with the jCH4 = 2 excited state of free methane. The (appro...

Most calculations of the vibrational scattering of diatom-atom collisions use the breathing sphere approximation (BSA) of orientation averaging the intermolecular potential. The resulting angularly symmetric potential can not cause rotational scattering. We determine the error introduced by the BSA into observables of the vibrational scattering of low-energy homonuclear diatom-atom collisions b...

Intermolecular interactions play a vital role in crystal structures. Therefore, we conducted a topological study, using Hirshfeld surfaces and atom in molecules (AIM) analysis, to decompose and analyze, respectively, the different intermolecular interactions in six hydrazone-diacetyl platinum(II) complexes. Using AIM and natural bond orbital (NBO) analyses, we determined the type, nature, and s...

Geometry optimizations were carried out for the (HF)2, (H2O)2, and HF–H2O intermolecular complexes using the MP2/aug-cc-pVXZ {X = 2, 3, 4, and 5} theoretical models on both the uncorrected and counterpoise (CP) corrected potential energy hypersurfaces (PES). Our results and the available literature data clearly show that extrapolation of intermolecular distances to the complete basis set (CBS) ...