分子动力学模拟中时间步长的选取非常重要，时间步长越短，计算时间越长。时间步长太长的话，模拟体系会出现偏差。一般来说，时间步长应该设为分子运动的最小振动周期的1/10
左右为宜。在化学分子中振动周期最短的是碳氢键的伸缩振动，其特征振动频率大约是3000cm-1，其振动周期大约是10fs。所以通常的分子动力学时间步长最高不能高于1fs。
http://blogold.chinaunix.net/u2/85704/showart_1884250.html
The choice of timestep
A key parameter in the integration algorithms is the integration timestep. To make the best use of the computer time, a large timestep should be used. However, too large a timestep causes instability and inaccuracy in the integration process.
Relation of timestep to molecular vibration
The timestep used depends on the model as well as the integrators. The main limitation imposed by the model is the highest-frequency motion that must be considered. A vibrational period must be split into at least 8-10 segments for models to satisfy the Verlet assumption that the velocities and accelerations are constant over the time
http://blogold.chinaunix.net/u2/85704/showart_1884250.html
The choice of timestep
A key parameter in the integration algorithms is the integration timestep. To make the best use of the computer time, a large timestep should be used. However, too large a timestep causes instability and inaccuracy in the integration process.
Relation of timestep to molecular vibration
The timestep used depends on the model as well as the integrators. The main limitation imposed by the model is the highest-frequency motion that must be considered. A vibrational period must be split into at least 8-10 segments for models to satisfy the Verlet assumption that the velocities and accelerations are constant over the time