NPT MD simulations allow to have fixed pressure, while the cell shape changes. At the moment only isotropic volume change is possible: the cell is scaled by a scalar factor, the angles stay the same and the ratio of length too. In order to observe phase transition, it's important that the cell can change shape (example: titanium hcp -> bcc transition around 1150K).
NPT Langevin comes from Grønbech-Jensen, N., & Farago, O. (2014). Constant pressure and temperature discrete-time Langevin molecular dynamics. The Journal of chemical physics, 141(19).
It's possible to implement a full anisotropic method (angles and length). In this paper, only the length degrees of freedom are describe. I suggest to have a look on LAMMPS implementation in C++: https://github.com/lammps/lammps/blob/develop/src/fix_press_langevin.cpp, which should be the inspiration of the current method.
NPT MD simulations allow to have fixed pressure, while the cell shape changes. At the moment only isotropic volume change is possible: the cell is scaled by a scalar factor, the angles stay the same and the ratio of length too. In order to observe phase transition, it's important that the cell can change shape (example: titanium hcp -> bcc transition around 1150K).
NPT Langevin comes from Grønbech-Jensen, N., & Farago, O. (2014). Constant pressure and temperature discrete-time Langevin molecular dynamics. The Journal of chemical physics, 141(19).
It's possible to implement a full anisotropic method (angles and length). In this paper, only the length degrees of freedom are describe. I suggest to have a look on LAMMPS implementation in C++: https://github.com/lammps/lammps/blob/develop/src/fix_press_langevin.cpp, which should be the inspiration of the current method.