Precise Calculation of the Local Pressure Tensor in Cartesian and Spherical Coordinates in LAMMPS

Takenobu Nakamura, Shuhei Kawamoto, Wataru Shinoda

Comput. Phys. Comm. 190, 120-128 (2015).

An accurate and efficient algorithm for calculating the 3D pressure field has been developed and implemented in the open-source molecular dynamics package, LAMMPS. Additionally, an algorithm to compute the pressure profile along the radial direction in spherical coordinates has also been implemented. The latter is particularly useful for systems showing a spherical symmetry such as micelles and vesicles. These methods yield precise pressure fields based on the Irving-Kirkwood contour integration and are particularly useful for biomolecular force fields. The present methods are applied to several systems including a buckled membrane and a vesicle.