Cooperative Roles of Charge Transfer and Dispersion Terms in Hydrogen-Bonded Networks of (H₂O)_n, n = 6, 11, and 16

Abstract

The perturbation expansion based on the locally-projected molecular orbital (LPMO PT) was applied to the study of the hydrogen-bonded networks of water clusters with up to 16 molecules. Utilizing the local nature of the occupied and excited MOs on each monomer, the charge-transfer and dispersion terms are evaluated for every pair of molecules. The two terms are strongly correlated with each other for the hydrogen-bonded pairs. The strength of the hydrogen bonds in the clusters is further classified by the types of the hydrogen donor and acceptor water molecules. The relative energies evaluated with the LPMO PT among the isomers of (H2O)6, (H2O)11, and (H2O)16 agree very well with those obtained from CCSD(T) calculations with large basis sets. The binding energy of the LPMO PT is approximately free of the basis set superposition errors caused both by the orbital basis inconsistency and by the configuration basis inconsistency.

Cryogenic ion trap vibrational spectroscopy of hydrogen-bonded clusters relevant to atmospheric chemistry

“…Working with cluster ions allows applying a combination of highly sensitive and selective mass spectrometric and laser spectroscopic techniques, developed over the last decades (see e.g. The properties of finite HBed clusters can be treated with higher level quantum chemical calculations than can be applied (with the same accuracy) to the more extended condensed phase systems [41][42][43][44][45]. [15][16][17][18][19][20][21][22][23][24][25][26][27] and references therein).…”

Understanding the structure and hydrogen bonding network of (H2O)32 and (H2O)33: an improved Monte Carlo temperature basin paving (MCTBP) method and quantum theory of atoms in molecules (QTAIM) analysis

“…10 Iwata et al used a locally-projected molecular orbital method to understand the cooperative role of charge transfer and dispersion terms in HB networks in water clusters. 11 Bako et al studied the hierarchy of cooperative effect of HB, characteristics of HB, and dipole moment in water monomer, small sized clusters, and large cage-like clusters. 12 The Bandyopadhyay group examined structures of larger water clusters in several works.…”

Electronic origin of the dependence of hydrogen bond strengths on nearest-neighbor and next-nearest-neighbor hydrogen bonds in polyhedral water clusters (H2O)n, n = 8, 20 and 24

“…In the previous studies 26 , the CT criteria helped to find the weak H bonds in some complex cage structures of water clusters and to locate the cyclic networks. Because the clusters studied in the present study are of polyhedral form, the O-O distance or O-HO distance can be used as the criteria of the H bond, as often used.…”

“…22,23 The zero-order energy is exactly free of Basis Set Superposition Error (BSSE) with any basis set, and because of the proper definition of the excited orbitals, the perturbation correction is approximately BSSE-free. The pairwise terms of the CT and Disp terms in the water clusters have been shown to be strongly correlated with the H bond distance in water clusters, 26,27 and they have been used as an alternative measure of the strength of the H bonds in analyzing the H bonded networks in (H 2 O) 20 and (H 2 O) 25 . 23,25 One of the advantages of this method is that the contribution to the interaction energy from the CT terms can be expressed by a sum of the terms of every pair of H bonded molecules as the contributions from the Disp terms are.…”