void PairYukawa::compute(int eflag, int vflag)

{

  int i,j,ii,jj,inum,jnum,itype,jtype;

  double xtmp,ytmp,ztmp,delx,dely,delz,ecoul,fpair;

  double rsq,r2inv,r,rinv,screening,forceyukawa,factor_coul;

  double xtmp,ytmp,ztmp,delx,dely,delz,evdwl,fpair;

  double rsq,r2inv,r,rinv,screening,forceyukawa,factor;

  int *ilist,*jlist,*numneigh,**firstneigh;

  ecoul = 0.0;

  evdwl = 0.0;

  if (eflag || vflag) ev_setup(eflag,vflag);

  else evflag = vflag_fdotr = 0;

  double **f = atom->f;

  int *type = atom->type;

  int nlocal = atom->nlocal;

  double *special_coul = force->special_coul;

  double *special_lj = force->special_lj;

  int newton_pair = force->newton_pair;

  inum = list->inum;

    for (jj = 0; jj < jnum; jj++) {

      j = jlist[jj];

      factor_coul = special_coul[sbmask(j)];

      factor = special_lj[sbmask(j)];

      j &= NEIGHMASK;

      delx = xtmp - x[j][0];

	screening = exp(-kappa*r);

	forceyukawa = a[itype][jtype] * screening * (kappa + rinv);

	fpair = factor_coul*forceyukawa * r2inv;

	fpair = factor*forceyukawa * r2inv;

	f[i][0] += delx*fpair;

	f[i][1] += dely*fpair;

	}

	if (eflag) {

	  ecoul = a[itype][jtype] * screening * rinv - offset[itype][jtype];

	  ecoul *= factor_coul;

	  evdwl = a[itype][jtype] * screening * rinv - offset[itype][jtype];

	  evdwl *= factor;

	}

	if (evflag) ev_tally(i,j,nlocal,newton_pair,

			     0.0,ecoul,fpair,delx,dely,delz);

			     evdwl,0.0,fpair,delx,dely,delz);

      }

    }

  }

  rinv = 1.0/r;

  screening = exp(-kappa*r);

  forceyukawa = a[itype][jtype] * screening * (kappa + rinv);

  fforce = factor_coul*forceyukawa * r2inv;

  fforce = factor_lj*forceyukawa * r2inv;

  phi = a[itype][jtype] * screening * rinv - offset[itype][jtype];

  return factor_coul*phi;

  return factor_lj*phi;

}