DNRF Centre Glass and Time, IMFUFA, Department of Sciences, Roskilde University, Roskilde, Denmark.
J Chem Phys. 2011 Feb 28;134(8):081102. doi: 10.1063/1.3558787.
Simulations involving the Lennard-Jones potential usually employ a cutoff at r = 2.5σ. This communication investigates the possibility of reducing the cutoff. Two different cutoff implementations are compared, the standard shifted potential cutoff and the less commonly used shifted forces cutoff. The first has correct forces below the cutoff, whereas the shifted forces cutoff modifies Newton's equations at all distances. The latter is nevertheless superior; we find that for most purposes realistic simulations may be obtained using a shifted forces cutoff at r = 1.5σ, even though the pair force is here 30 times larger than at r = 2.5σ.
模拟通常采用 Lennard-Jones 势能的截断半径 r = 2.5σ。本研究探讨了降低截断半径的可能性。比较了两种不同的截断实现方法，标准移位势截断和较少使用的移位力截断。前者在截断半径以下具有正确的力，而移位力截断则在所有距离上修改牛顿方程。然而，后者更为优越；我们发现，对于大多数目的，即使在 r = 1.5σ 处使用移位力截断时，也可以获得现实的模拟结果，尽管此时对力的计算是在 r = 2.5σ 处的 30 倍。
