lammps/lib/cuda/pair_lj_expand_cuda_kernel_...

34 lines
1.4 KiB
Plaintext

/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
Original Version:
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
See the README file in the top-level LAMMPS directory.
-----------------------------------------------------------------------
USER-CUDA Package and associated modifications:
https://sourceforge.net/projects/lammpscuda/
Christian Trott, christian.trott@tu-ilmenau.de
Lars Winterfeld, lars.winterfeld@tu-ilmenau.de
Theoretical Physics II, University of Technology Ilmenau, Germany
See the README file in the USER-CUDA directory.
This software is distributed under the GNU General Public License.
------------------------------------------------------------------------- */
__device__ inline F_FLOAT PairLJExpandCuda_Eval(const F_FLOAT& rsq,const int ij_type,F_FLOAT& factor_lj,int& eflag, ENERGY_FLOAT& evdwl)
{
const F_FLOAT r = _SQRT_(rsq);
const F_FLOAT rshift = r - _shift[ij_type];
const F_FLOAT rshiftsq = rshift*rshift;
const F_FLOAT r2inv = F_F(1.0)/rshiftsq;
const F_FLOAT r6inv = r2inv*r2inv*r2inv;
const F_FLOAT forcelj = r6inv * (_lj1[ij_type]*r6inv - _lj2[ij_type]);
if(eflag) evdwl += factor_lj*(r6inv*(_lj3[ij_type]*r6inv-_lj4[ij_type]) - _offset[ij_type]);
return factor_lj*forcelj*(F_F(1.0)/rshift)*(F_F(1.0)/r);
}