remove more dead code

  fy = dely*fpair/rij;

  fz = delz*fpair/rij;

  if (R <= EPSILON) { // in contact

    // relative translational velocity

    vr1 = v[i][0] - v[j][0];

    vr2 = v[i][1] - v[j][1];

    vr3 = v[i][2] - v[j][2];

    // normal component

    vnnr = vr1*delx + vr2*dely + vr3*delz;

    vn1 = delx*vnnr * rsqinv;

    vn2 = dely*vnnr * rsqinv;

    vn3 = delz*vnnr * rsqinv;

  }

  f[i][0] += fx;

  f[i][1] += fy;

  f[i][2] += fz;