Toward a realistic density functional theory potential energy surface for the H5+ cluster

Abstract

The potential energy surface of H(5)(+) is characterized using density functional theory. The hypersurface is evaluated at selected configurations employing different functionals, and compared with results obtained from ab initio CCSD(T) calculations. The lowest ten stationary points (minima and saddle-points) on the surface are located, and the features of the short-, intermediate-, and long-range intermolecular interactions are also investigated. A detailed analysis of the surface's topology, and comparisons with extensive CCSD(T) results, as well as a recent ab initio analytical surface, shows that density functional theory calculations using the B3(H) functional represent very well all aspects studied on the H(5)(+) potential. These include the tiny energy difference between the minimum at 1-C(2v) configuration and the 2-D(2d) one corresponding to the transition state for the proton transfer between the two equivalent C(2v) minima, and also the correct asymptotic behavior of the long-range interactions. The calculated binding energy and dissociation enthalpies compare very well with previous benchmark coupled-cluster ab initio data, and with experimental data available. Based on these results the use of such approach to perform first-principles molecular dynamics simulations could provide reliable information regarding the dynamics of protonated hydrogen clusters.

Vibrational dynamics of the ${\rm H}_5^+$H5+ and its isotopologues from multiconfiguration time-dependent Hartree calculations

“…6,9 Numerous electronic structure calculations and normal-node frequencies at different levels of theory have been reported for the H + 5 . 8,19,20 However, it is clear that standard zeroth-order methods of its spectroa) E-mail: rita@iff.csic.es. scopic analysis are useless, and to understand the vibrations of H + 5 proper nuclear quantum mechanical treatments to count with anharmonic effects together with an accurate representation of its potential surface at the configuration space of interest should be considered.…”

“…21 and references therein) for high-dimensional molecular systems. 22 In particular, up to date several H + 5 surfaces are available in the literature, 10,12,20,23 with each of them based on different theoretical approaches. In particular, various fitting procedures to ab initio data using site-site interactions, diatomics-in molecules, triatomic-in-molecules, generalized many-body expansion, and permutationally invariant functional forms for the parameterization of the surface have been reported.…”

Infrared spectrum of H5+and D5+: The simplest shared-proton model

“…To date, several full dimensional potential energy surfaces (PESs) for H 5 + are available [8][9][10]. In this Rapid Communication we use the accurate triatomics in molecules based analytical PES [9], fitted to high-level ab initio points [11], together with the electric dipole moment surface recently reported and used to perform spectra simulations at zero temperature [12].…”

Simulation of the infrared predissociation spectra of H5+

“…Several * Corresponding author: octavio.roncero@csic.es global potential-energy surfaces (PESs) of increasing accuracy [35][36][37][38][39][40][41] have emerged in the last years. An energy diagram for this system is shown in Fig.…”