amep.utils.dr_wca

amep.utils.dr_wca(r: float | ndarray, eps: float = 10.0, sig: float = 1.0)

First derivative of the Weeks-Chandler-Anderson (WCA) potential. [1]

References

[1]

J. D. Weeks, D. Chandler, and H. C. Andersen, Role of Repulsive Forces in Determining the Equilibrium Structure of Simple Liquids, J. Chem. Phys. 54, 5237 (1971). https://doi.org/10.1063/1.1674820

Parameters:

• r (float | np.ndarray) – Distances.

• eps (float, optional) – Strength of the potential. The default is 10.0.

• sig (float, optional) – Effective particle diameter. The default is 1.0.

Returns:

dr – First derivative.

Return type:

float | np.ndarray