Per-Olof Åstrand

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Molecular dynamics simulations have been performed with two reactive force fields to investigate the structure of a Pt100 cluster adsorbed on the three distinct sides of a carbon platelet. A revised Reax force field for the carbon-platinum system is presented. In the simulations, carbon platelet edges both with and without hydrogen termination have been(More)
An open source software system called GaussDal for management of results from quantum chemical computations is presented. Chemical data contained in output files from different quantum chemical programs are automatically extracted and incorporated into a relational database (PostgreSQL). The Structural Query Language (SQL) is used to extract combinations of(More)
With fossil fuel reserves on the decline, there is increasing focus on the design and development of low-cost organic photovoltaic devices, in particular, dye-sensitized solar cells (DSSCs). The power conversion efficiency (PCE) of a DSSC is heavily influenced by the chemical structure of the dye. However, as far as we know, no predictive quantitative(More)
We use molecular dynamics simulations in applied thermal gradients to study thermomolecular orientation (TMO) of size-asymmetric dipolar dumbbells with different molecular dipole moments. We find that the direction of the TMO is the same as in apolar dumbbells of the same size, i.e. the smaller atom in the dumbbell tends to orient towards the colder(More)
A crucial component of research in the field of quantitative structure-activity/property relationships is the identification of molecular descriptors relevant to the activity or property of interest. Descriptors based on the topology of the electron density as formulated in Bader's theory of atoms in molecules are investigated in detail in this work. In a(More)
The relationship between the molecular electronic structure and the position of the absorption maxima in 191 azobenzene dyes has been studied by quantitative structure-property relations. A strong linearity is observed between the nitrogen-nitrogen bond length and the absorption wavelength with a squared correlation coefficient of 0.90. Bond lengths and(More)
The microscopic electric polarization in terms of the dipole-dipole polarizability and its second hyperpolarizability of aligned films and ropes of carbon nanotubes has been studied theoretically by a point-dipole interaction model. The results show clearly the influence of intertube interactions on the microscopic polarization demonstrating the sensitivity(More)
We use density functional theory to investigate the impact that strong electric fields have on the structure and energetics of small lithium ion-water clusters, Li(+)·nH2O, with n = 4 or 6. We find that electric field strengths of ∼0.5 V/Å are sufficient to break the symmetry of the n = 4 tetrahedral energy minimum structure, which undergoes a(More)
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