Department of Polymer Science, The University of Akron, Akron, Ohio 44325, USA.
J Phys Chem B. 2013 Aug 29;117(34):10035-45. doi: 10.1021/jp404629a. Epub 2013 Aug 15.
An ab initio-based improved force field is reported for poly(3-hexylthiophene) (P3HT) in the solid state, deriving torsional parameters and partial atomic charges from ab initio molecular structure calculations with explicit treatment of the hexyl side chains. The force field is validated by molecular dynamics (MD) simulations of solid P3HT with different molecular weights including calculation of structural parameters, mass density, melting temperature, glass transition temperature, and surface tension. At 300 K, the P3HT crystalline structure features planar backbones with non-interdigitated all-trans hexyl side chains twisted ~90° from the plane of the backbone. For crystalline P3HT with infinitely long chains, the calculated 300 K mass density (1.05 g cm(-3)), the melting temperature (490 K), and the 300 K surface tension (32 mN/m) are all in agreement with reported experimental values, as is the glass transition temperature (300 K) for amorphous 20-mers.
报道了一种基于从头算的改进的聚（3-己基噻吩）（P3HT）的固态力场，该力场通过对具有明确的己基侧链的分子结构进行从头算分子结构计算，得到了扭转参数和部分原子电荷。该力场通过不同分子量的固态 P3HT 的分子动力学（MD）模拟进行了验证，包括结构参数、质量密度、熔点、玻璃化转变温度和表面张力的计算。在 300 K 时，P3HT 的晶体结构特征为具有非交错的全反式己基侧链的平面骨架，这些侧链从骨架平面扭曲约 90°。对于具有无限长链的结晶 P3HT，计算得到的 300 K 质量密度（1.05 g cm(-3))、熔点（490 K）和 300 K 表面张力（32 mN/m）都与报道的实验值一致，无定形 20 聚物的玻璃化转变温度（300 K）也是如此。
