Homec4science
Diffusion lammps (lammm-master) Browse

lammps/lib/cuda/pair_lj_charmm_coul_charmm_cuda_kernel_nc.cu
860bca7d5e5dlammm-master

Last Change
Raw File

pair_lj_charmm_coul_charmm_cuda_kernel_nc.cu
View Options

/* ----------------------------------------------------------------------
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 PairLJCharmmCuda_Eval(const F_FLOAT& rsq,const int ij_type,F_FLOAT& factor_lj,int& eflag, ENERGY_FLOAT& evdwl)
{
const F_FLOAT r2inv = F_F(1.0)/rsq;
const F_FLOAT r6inv = r2inv*r2inv*r2inv;
F_FLOAT forcelj = r6inv * (_lj1[ij_type]*r6inv - _lj2[ij_type]);
F_FLOAT philj,switch1;
if(rsq > _cut_innersq_global)
{
switch1 = (_cutsq_global-rsq) * (_cutsq_global-rsq) *
(_cutsq_global + F_F(2.0)*rsq - F_F(3.0)*_cut_innersq_global) * _denom_lj_inv;
const F_FLOAT switch2 = F_F(12.0)*rsq * (_cutsq_global-rsq) *
(rsq-_cut_innersq_global) * _denom_lj_inv;
philj = r6inv * (_lj3[ij_type]*r6inv - _lj4[ij_type]);
forcelj = forcelj*switch1 + philj*switch2;
}
if (eflag)
{
ENERGY_FLOAT evdwl_tmp = factor_lj;
if (rsq > _cut_innersq_global)
{
evdwl_tmp*=philj*switch1;
}
else
evdwl_tmp*= r6inv * (_lj3[ij_type]*r6inv - _lj4[ij_type]);
evdwl+=evdwl_tmp;
}
return factor_lj*forcelj*r2inv;
}
__device__ inline F_FLOAT CoulCharmmCuda_Eval(const F_FLOAT& rsq,F_FLOAT& factor_coul,int& eflag, ENERGY_FLOAT& ecoul, F_FLOAT qij)
{
F_FLOAT forcecoul;
ENERGY_FLOAT ecoul_tmp = forcecoul = _qqrd2e * qij *_RSQRT_(rsq)*factor_coul;
if (rsq > _cut_coul_innersq_global) {
const F_FLOAT switch1 = (_cut_coulsq_global-rsq) * (_cut_coulsq_global-rsq) *
(_cut_coulsq_global + F_F(2.0)*rsq - F_F(3.0)*_cut_coul_innersq_global) * _denom_coul_inv;
ecoul_tmp *= switch1;
const F_FLOAT switch2 = F_F(12.0)*rsq * (_cut_coulsq_global-rsq) *
(rsq-_cut_coul_innersq_global) * _denom_coul_inv;
forcecoul *= switch1 + switch2;
}
if(eflag)
{
ecoul += ecoul_tmp*factor_coul;
}
return forcecoul*(F_F(1.0)/rsq);
}
c4science · Help