We developed a rapid method to calculate the average electronic structure properties of large ensembles of conjugated polymer chains sampling their conformational space. This is achieved by using the localized molecular orbital (MO) method to rapidly compute the MOs and their energies for isolated polymer chains and through using a calibration scheme to further correct the obtained energies by comparison with a few accurate calculations. The method is applied to the study of the density of states and orbital localization characteristics for five polymers. It is shown that all key properties of the individual chain related to the charge mobility can be rationalized in terms of the properties of the constituent monomers, their interaction, and the conformational flexibility of the chain. More specifically we identify the features that lead to greater charge delocalization. Finally, we discuss the prospect of using this method for a computational high-throughput screening of conjugated polymers.

The microscopic structure of high mobility semiconducting polymers is known to be essential for their performance but it cannot be easily deduced from the available experimental data. A series of...

We employ a rapid method for computing the electronic structure and orbital localization characteristics for a sample of 36 different polymer backbone structures. This relatively large sample derived from recent...

A combination of different molecular simulation techniques was used to begin to uncover the mechanism behind the compositional tuning of gas sorption behavior in a multicomponent porous molecular crystal, CC1·CC3 n ·CC4 1–n , where 0 < n < 1. Gas access to formally occluded voids was found to be allowed through a cooperative diffusion mechanism that requires the presence of the guest for the channel to briefly open. Molecular dynamics simulations and dynamic void analysis suggest two putative diffusion mechanisms. We propose that the gas diffusion is controlled by the cage vertices that surround the void, with the slightly smaller and more mobile cyclopentane vertices in CC4 allowing more facile nitrogen diffusion than the cyclohexane vertices in CC3. A combination of sorption simulations, void analysis, and statistical calculations suggests the diffusion mechanism may rely upon the presence of two CC4 molecules adjacent to the occluded voids.

Decades of work in the field of computational study of semiconducting polymers using atomistic models illustrate the challenges of generating equilibrated models for this class of materials. While adopting a...