 		}
 	else	// large rigid bodies
 		{
-		unsigned int window_size = 16;			// some fixed value divisble by nmax
+		unsigned int window_size = 128;			// some fixed value divisble by nmax
 		unsigned int block_size = window_size;
 		dim3 force_grid(n_bodies, 1, 1);
 		dim3 force_threads(block_size, 1, 1); 

        }
    else
        {
        block_size = 32; 
        dim3 particle_grid(n_group_bodies, 1, 1);
        dim3 particle_threads(block_size, 1, 1);                                                
        gpu_nve_rigid_step_two_particle_sliding_kernel<<< particle_grid, particle_threads >>>(pdata.vel,

        }
    else
        {
        block_size = 128; 	// chosen to be divisible by nmax
        dim3 particle_grid(n_group_bodies, 1, 1);
        dim3 particle_threads(block_size, 1, 1);
        
