AN ANALYSIS OF THE ACCURACY OF LANGEVIN AND MOLECULAR-DYNAMICS ALGORITHMS
AN ANALYSIS OF THE ACCURACY OF LANGEVIN AND MOLECULAR-DYNAMICS ALGORITHMS
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DOI：
10.1080/00268978800101881
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发表时间：
1988-12-20
影响因子：
1.7
通讯作者：
SZABO, A
中科院分区：
文献类型：
--
作者：
PASTOR, RW;BROOKS, BR;SZABO, A
均方的谐振子的位置和速度的解析表达式推导出的Langevin动力学算法有效的高，低摩擦限制，和Verlet算法。对于参数的典型值，位置误差很小。然而，如果速度是由通常的韦尔莱形式定义的，那么朗之万算法的动能（以及因此计算的温度）可能会有百分之几的误差。如果使用Bunger-Brooks-Karplus算法来计算位置，则简单地重新定义速度会大大提高动能。此外，由于速度和位置误差的抵消，正确的维里得到。研究了在扩散算法中包含力导数的影响。位置和速度的平均值计算的Verlet算法为任意初始条件，并在总能量和维里的误差进行了分析。连接与朗之万算法，它示出了谐振子，不同的定义的速度需要优化计算的温度，压力和总能量，分别。
Analytic expressions for mean squared positions and velocities of a harmonic oscillator are derived for Langevin dynamics algorithms valid in the high and low friction limits, and for the Verlet algorithm. For typical values of the parameters, errors in the positions are small. However, if the velocity is defined by the usual Verlet form, kinetic energies (and therefore calculated temperatures) can be in error by several per cent for the Langevin algorithms. If the Bunger-Brooks-Karplus algorithm is used to calculate positions, a simple redefinition of the velocity results greatly in improved kinetic energies. In addition, due to cancellation of errors in the velocities and the positions, the correct virial is obtained. The effect of including the force derivative in diffusive algorithms is examined. Positional and velocity averages are calculated for the Verlet algorithm for arbitrary initial conditions, and errors in the total energy and virial are analysed. Connection is made with the Langevin algorithms, and it is shown for harmonic oscillators that different definitions of the velocity are required to optimally calculate the temperature, pressure, and total energy, respectively.