Tor Vergata University of Rome, via della Ricerca scientifica 1, I-00133 Rome, Italy.
J Chem Phys. 2013 Jan 28;138(4):044110. doi: 10.1063/1.4776196.
We present a generalized version of the ITIM algorithm for the identification of interfacial molecules, which is able to treat arbitrarily shaped interfaces. The algorithm exploits the similarities between the concept of probe sphere used in ITIM and the circumsphere criterion used in the α-shapes approach, and can be regarded either as a reference-frame independent version of the former, or as an extended version of the latter that includes the atomic excluded volume. The new algorithm is applied to compute the intrinsic orientational order parameters of water around a dodecylphosphocholine and a cholic acid micelle in aqueous environment, and to the identification of solvent-reachable sites in four model structures for soot. The additional algorithm introduced for the calculation of intrinsic density profiles in arbitrary geometries proved to be extremely useful also for planar interfaces, as it allows to solve the paradox of smeared intrinsic profiles far from the interface.
我们提出了一种用于识别界面分子的 ITIM 算法的广义形式，该算法能够处理任意形状的界面。该算法利用了 ITIM 中探针球概念与 α-形状方法中外接球准则之间的相似性，既可以看作是前者的参考系独立版本，也可以看作是后者的扩展版本，后者包括了原子排斥体积。新算法应用于计算水在十二烷基磷酸胆碱和胆酸胶束在水相环境中的固有取向序参数，并用于识别四个煤烟模型结构中溶剂可及的位点。为任意几何形状计算固有密度分布而引入的附加算法对于平面界面也非常有用，因为它可以解决远离界面的固有密度分布模糊的悖论。
