New energy partitioning scheme based on the self-consistent charge and configuration method for subsystems: Application to water dimer system

Abstract

The charge-transfer energy in water dimer is analyzed. The analysis is based on self-consistent charge and configuration method for subsystems (SCCCMS). The SCCCMS, as such, is not restricted to any computational schemes and can be applied at Hartree–Fock (HF), post-HF, and density functional levels of theory. In our approach, the interaction energy is decomposed into deformation (DEF), electrostatic (ES), polarization (P), charge transfer (CT), and exchange (EX) [exchange–correlation (XC)] contributions. The CT energy is derived from the energy surface spanned in the populational space. The intermediate results obtained during construction of this energy surface, such as chemical potentials, hardness and softness parameters, are of particular interest in the theory of chemical reactivity and, thus, these values are discussed as well. The influence of basis set and computational method is analyzed. The numerical values of the energy components obtained at the HF level of theory are compared with those of Kitaura–Morokuma (KM) and reduced variational space (RVS) analyses. It is shown that SCCCMS correctly describes the polarization process. The CT contribution is less dependent on the basis set than KM or RVS scheme and is free from the basis set superposition error (BSSE). It is demonstrated that the CT energy is of little importance for the water dimer. In addition, the amount of CT calculated in our scheme is almost identical to that obtained from the supermolecule calculations.

An efficient water force field calibrated against intermolecular THz and Raman spectra

“…For a hydrogen bonded water dimer with an H• • • M distance of 1.85 Å, the amount of charge transferred is 0.025 e, which is consistent with values reported from various QM calculations at different levels of theory ranging from HF to MP2. [52][53][54][55]57 A water molecule in a liquid water box, on the other hand, is neutral in average, but its charge fluctuates with a standard deviation of 0.013 e [ Fig. 5(a)].…”

“…It is well established that hydrogen bonding causes a small amount of charge to flow from the hydrogen bond acceptor to the hydrogen bond donor. 27,[52][53][54][55][56][57][58] It has been demonstrated by Torii that a very simple treatment of this effect, where the transferred charge is defined as a function of the hydrogen bond length, can capture the intensity of the hydrogen bond vibration band. 58 In these simulations, however, separate sets of charges were used for the force field and for the calculation of the THz spectrum.…”

A periodic energy decomposition analysis method for the investigation of chemical bonding in extended systems

“…A nonexhaustive list of approaches in this category is the Constrained Space Orbital Variation (CSOV) scheme developed by Bagus et al, 28 the natural energy decomposition analysis (NEDA) by Glendening and Streitwieser, 29 the reduced variational selfconsistent field (RVS-SCF) approach by Stevens and Fink, 30 the AIM-based decomposition scheme by Francisco et al, 31 a steric analysis by Liu, 32 and the schemes by Mayer 33 and Korchowiec. 34 A slightly different method employing absolutely localized molecular orbitals (ALMO) is the recently developed ALMO-EDA by Head-Gordon and co-workers 35 which can also be applied to correlated wave functions. 36 The blocklocalized wave function (BLW) method (BLW-ED) based on valence-bond theory has been put forward by Mo.…”

DFT studies of cation binding by β-cyclodextrin

“…Many decomposition schemes were proposed in the literature [17,[37][38][39][40][41]. We have chosen ETS scheme of Ziegler and Rauk [17].…”