Global Potential Energy Minima of C₆₀(H₂O)_n Clusters

Abstract

Likely candidates for the global potential energy minima of C60(H2O)n clusters with n < or = 21 are found using basin-hopping global optimization. The potential energy surfaces are constructed using the TIP4P intermolecular potential for the water molecules, a Lennard-Jones water-fullerene potential, and a water-fullerene polarization potential, which depends on the first few nonvanishing C60 multipole polarizabilities. This combination produces a rather hydrophobic water-fullerene interaction. As a consequence, the water component of the lowest C60(H2O)n minima is quite closely related to low-lying minima of the corresponding TIP4P (H2O)n clusters. In most cases, the geometrical substructure of the water molecules in the C60(H2O)n global minimum coincides with that of the corresponding free water cluster. Exceptions occur when the interaction with C60 induces a change in geometry. This qualitative picture does not change significantly if we use the TIP3P model for the water-water interaction. Structures such as C60@(H2O)60, in which the water molecules surround the C60 fullerene, correspond to local minima with much higher potential energies. For such a structure to become the global minimum, the magnitude of the water-fullerene interaction must be increased to an unphysical value.

Adsorption of molecular hydrogen on coronene with a new potential energy surface

“…Global minima were obtained using the BH 62 or Monte Carlo (MC) minimization 63 method, successfully employed before for both neutral 62,64,65 and charged atomic and molecular clusters [66][67][68][69][70][71] , along with many other applications. 72 This technique is a stochastic method that involves perturbation followed by minimization at each step.…”

Ion–Molecule Reactions in Helium Nanodroplets Doped with C60 and Water Clusters

“…The interaction of water molecules with neutral C 60 has been the subject of several theoretical studies that employed semiempirical interaction potentials [16] or density functional methods. [17] To the best of our knowledge, the work presented herein is the first ab initio study of charged C 60 (H 2 O) n + .…”

Efficiency of tabu‐search‐based conformational search algorithms

“…In the MCM and BH approaches, each randomly generated structure is optimized, and the resulting minima are used within the MC. This resetting of the geometry before the new perturbation strongly increases the efficiency as was shown in many examples, for example, Lennard-Jones clusters, 7,9,48 water shells, 49 and peptides.…”