LAMMPS WWW Site - LAMMPS Documentation - LAMMPS Mailing List Archives
[lammps-users] How to use molecular's quaternions for orientation-dependent forces calculation with "hybrid sphere molecular" style?
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[lammps-users] How to use molecular's quaternions for orientation-dependent forces calculation with "hybrid sphere molecular" style?


From: RainMan <debianfans@...24...>
Date: Sat, 23 Sep 2017 19:26:01 +0200

Dear LAMMPSers,

I am going to use Lammps to calculateĀ orientation-dependent forces on finite size rigid bodies with

----------------------------------------------
atom_style hybrid sphere molecular
...
fix Rigids all rigid moleculeĀ 
...
----------------------------------------------

Assuming the force coefficients of a specific shaped rigid body are pre-calculated from different Euler angles (a_x, a_y, a_z), and the uniform force field (electric/fluid field, etc ) orientation is fix at Z+ direction. Since "fix rigid" does calculate the quaternion information for each rigid body, therefore the force coefficient can be calculated like: coeff_force = Func(field_direction, quat_rigid) via the pre-calculated data (interpolation utilized).

My question is: how to use the per rigid/molecular quaternion information "quat[ibody]" for
1) created a new fix for the orientation-dependent forces calculation

and

2) if Lammps is called as static library for other program, how we can get the quat[ibody] information?

The problem might be easy for you, but I am not familiar with LAMMPS programming, and want to get some advice or insight before I dig into this issue.

best regards,

David