Normal mode analysis of van der Waals vibrations
- 1 August 1991
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 95 (3) , 1577-1587
- https://doi.org/10.1063/1.461072
Abstract
Two algorithms are presented for calculation of the van der Waals modes of weakly bound clusters. Both methods rely on the harmonic normal mode approximation and a chosen intermolecular potential. These calculational techniques differ specifically in the form of the force field employed: one method uses the total (both intra- and intermolecular) force field for the cluster and the other uses only the intermolecular force field. Both methods require rather elaborate coordinate transformation and their first and second partial derivatives; these are provided in detail. The two calculations generate eigenvalues and eigenvectors that are in complete agreement with one another for a given potential. The methods insure that the van der Waals modes are calculated at the proper cluster equilibrium configuration for which all torques and forces on molecules and/or atoms are effectively zero. Examples are presented for (H2O)n (n=2,...,7), benzene clustered with water, methane, and ammonia, and a number of different intermolecular potentials. Some of the observed heterogeneous cluster van der Waals modes are reassigned in light of these new results.Keywords
This publication has 33 references indexed in Scilit:
- Energy parameters in polypeptides. 9. Updating of geometrical parameters, nonbonded interactions, and hydrogen bond interactions for the naturally occurring amino acidsThe Journal of Physical Chemistry, 1983
- Intermolecular and intramolecular V→V transfer in the vibrational predissociation of some polyatomic van der Waals moleculesThe Journal of Chemical Physics, 1981
- Force field, dipole moment derivatives, and vibronic constants of benzene from a combination of experimental and a b i n i t i o quantum chemical informationThe Journal of Chemical Physics, 1981
- Quantum and statistical mechanical studies of liquids. 3. Deriving intermolecular potential functions for the water dimer from ab initio calculationsJournal of the American Chemical Society, 1979
- Computation of the intermolecular vibrational modes of a tetrahedral water pentamer at the core of an ice-like water clusterThe Journal of Physical Chemistry, 1975
- Vibrational frequencies of water clustersThe Journal of Physical Chemistry, 1974
- Intermolecular potentials from crystal data. III. Determination of empirical potentials and application to the packing configurations and lattice energies in crystals of hydrocarbons, carboxylic acids, amines, and amidesThe Journal of Physical Chemistry, 1974
- Consistent Force Field Calculations. II. Crystal Structures, Sublimation Energies, Molecular and Lattice Vibrations, Molecular Conformations, and Enthalpies of AlkanesThe Journal of Chemical Physics, 1970
- Calculation of Ground State Vibrational Structure and Phonons of the Isotopic Benzene CrystalsThe Journal of Chemical Physics, 1970
- The force field, vibration frequencies, normal co-ordinates, infra-red and Raman intensities for benzenePhilosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1955