Vibrationally averaged isotropic dispersion energy coefficients of the parahydrogen dimer.

We compare the sum-over-states and coupled cluster linear response formalisms for the determination of imaginary-frequency polarizabilities of H(2). Using both approaches, we compute isotropic dispersion energy coefficients C(n) (n = 6, 8, 10) for H(2)-H(2) molecular pairs over a wide range of H(2) bond lengths. We present vibrationally averaged dispersion energy coefficients for H(2)-H(2), H(2)-D(2), and D(2)-D(2) molecular pairs and examine the coefficients' convergence with respect to basis set.

Study of polycyclic aromatic hydrocarbons adsorbed on graphene using density functional theory with empirical dispersion correction.

The interaction of polycyclic aromatic hydrocarbon molecules with hydrogen-terminated graphene is studied using density functional theory with empirical dispersion correction. The effective potential energy surfaces for the interaction of benzene, C(6)H(6), naphthalene, C(10)H(8), coronene, C(24)H(12), and ovalene, C(32)H(14), with hydrogen-terminated graphene are calculated as functions of the molecular displacement along the substrate. The potential energy surfaces are also described analytically using the lowest harmonics of the Fourier expansion.

Atomic charge densities generated using an iterative stockholder procedure.

A simple computational technique is introduced for generating atomic electron densities using an iterated stockholder procedure. It is proven that the procedure is always convergent and leads to unique atomic densities. The resulting atomic densities are shown to have chemically intuitive and reasonable charges, and the method is used to analyze the hydrogen bonding in the minimum energy configuration of the water dimer and charge transfer in the borazane molecule.

Redefining the atom: atomic charge densities produced by an iterative stockholder approach.

A new, simple, computational technique allows molecular electron densities to be divided into atoms which have intuitively correct shapes and charges.