Departamento de Física Fundamental II and IUdEA, Universidad de La Laguna, 38205 Tenerife, Spain.
J Chem Phys. 2011 Sep 28;135(12):124303. doi: 10.1063/1.3640804.
Likely candidates for the lowest minima of water clusters (H(2)O)(N) for N ≤ 20 interacting with a uniform electric field strength in the range E ≤ 0.6 V/Å have been identified using basin-hopping global optimization. Two water-water model potentials were considered, namely TIP4P and the polarizable Dang-Chang potential. The two models produce some consistent results but also exhibit significant differences. The cluster internal energy and dipole moment indicate two varieties of topological transition in the structure of the global minimum as the field strength is increased. The first takes place at low field strengths (0.1 V/Å<E < 0.2 V/Å) and reorganizes the hydrogen-bonds to orient the water permanent dipoles along the field. The second type of transition occurs at larger field strengths (0.3 V/Å<E < 0.5 V/Å) and corresponds to an extensive structural reorganization, where several hydrogen-bonds break as the cluster stretches along the field direction, the larger clusters (N > 10) usually forming helical structures.
使用 basin-hopping 全局优化方法，确定了相互作用的均匀电场强度在 E ≤ 0.6 V/Å 范围内的最低水团簇（H(2)O)(N）的可能候选物，其中 N ≤ 20。考虑了两种水-水模型势能，即 TIP4P 和极化 Dang-Chang 势能。这两种模型产生了一些一致的结果，但也表现出显著的差异。随着场强的增加，簇内能量和偶极矩表明全局最小值结构中存在两种拓扑转变。第一种发生在低场强（0.1 V/Å<E < 0.2 V/Å），重组氢键以使水永久偶极子沿场取向。第二种类型的转变发生在较大的场强（0.3 V/Å<E < 0.5 V/Å），对应于广泛的结构重组，其中几个氢键断裂，簇沿场方向伸展，较大的簇（N > 10）通常形成螺旋结构。
