Comparison of two ways to decompose intermolecular interactions for hydrogen-bonded dimer systems

Abstract

Articles you may be interested inIntermolecular vibrational modes and orientational dynamics of cooperative hydrogen-bonding dimer of 7azaindole in solution Comment on "Anisotropic intermolecular interactions in van der Waals and hydrogen-bonded complexes: What can we get from density-functional calculations?" [J.In this work we test two ab initio methodologies which allow the decomposition of the total intermolecular interaction energy into physically meaningful contributions, namely, the symmetry adapted perturbation theory ͑SAPT͒ and the use of localized orbitals within a Møller-Plesset perturbation scheme. The accuracy of the two different methods is compared to supermolecular results, within MP2 and coupled-cluster theory within single and double excitations, with perturbative estimates of the amplitudes of triple excitations ͓CCSD͑T͔͒. Some relations between the different approaches are conjectured from theoretical considerations, and are confirmed by numerical results. The corresponding calculations have been performed for three model dimers: two NH 3¯H2 O dimers, with NH 3 acting once as a proton acceptor and once as a proton donor, and the NH 4 ϩ¯H 2 O considered as a prototype of the ion-molecule interaction. We may conclude that third-order terms in SAPT help significantly to reproduce the Hartree-Fock induction and the relaxed, total dispersion in the LMP2 decomposition.

Geometrical frustration of an argon monolayer adsorbed on the MgO (100) surface: An accurate periodicab initiostudy

“…54,55 The intrapart, i.e., the reduction of the correlation energy of the electrons of the Ar atom due to exchange compression caused by the presence of the electron density of the Na 2 Mg 3 O 4 cluster and vice versa is, on the other hand, rather well described. Indeed, as is evident from Fig.…”

Periodic ab initio estimates of the dispersive interaction between molecular nitrogen and a monolayer of hexagonal BN

“…In the present case, we actually have two separate subsystems, the molecule and the slab, and are interested in the correlation interactions between rather than inside them. Therefore, the biexcitations, for which one WF (and the respective domain) belongs to the slab, the other (with its domain) to the molecule, are representing the dispersion 37 and are the most important for our purposes. However, the intramolecular and intra-slab biexcitations cannot simply be neglected, since this would lead to significant overestimation of the interaction energy, especially at short molecule-surface distances.…”

Electronic Density Approaches to the Energetics of Noncovalent Interactions

“…Higher levels of theory yield more elaborate representations of E int [5,7,9]. The various contributions to E int , as in eq.…”

“…(1) has made perturbation theory an attractive alternative [7][8][9]. This directly produces the interaction energy E int between the components M i , without the need to take differences between large numbers.…”