Chen Chunxia, Depa Praveen, Maranas Janna K, Garcia Sakai Victoria
Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
J Chem Phys. 2008 Mar 28;128(12):124906. doi: 10.1063/1.2833545.
We evaluate explicit atom, united atom, and coarse-grained force fields for molecular dynamics simulation of poly(methyl methacrylate) (PMMA) by comparison to structural and dynamic neutron scattering data. The coarse-grained force field is assigned based on output of the united atom simulation, for which we use an existing force field. The atomic structure of PMMA requires the use of two types of coarse-grained beads, one representing the backbone part of the repeat unit and the other representing the side group. The explicit atom description more closely resembles dynamic experimental data than the united atom description, although the latter provides a reasonable approximation. The coarse-grained description provides structural and dynamic properties in agreement with the united atom description on which it is based, while allowing extension of the time trajectory of the simulation.
我们通过与结构和动态中子散射数据进行比较，评估了用于聚甲基丙烯酸甲酯（PMMA）分子动力学模拟的显式原子、联合原子和粗粒化力场。粗粒化力场是根据联合原子模拟的输出分配的，为此我们使用了现有的力场。PMMA的原子结构需要使用两种类型的粗粒化珠子，一种代表重复单元的主链部分，另一种代表侧基。显式原子描述比联合原子描述更接近动态实验数据，尽管后者提供了合理的近似值。粗粒化描述提供的结构和动态特性与它所基于的联合原子描述一致，同时允许扩展模拟的时间轨迹。
