       vars->gpu_lambdaCoulomb,
       vars->gpu_isFraction,
       box);
+  cudaDeviceSynchronize();
   checkLastErrorCUDA(__FILE__, __LINE__);
 
   // ReduceSum

                       cudaMemcpyHostToDevice));
  gpuErrchk(cudaMemcpy(vars->gpu_z, coords.z, atomNumber * sizeof(double),
                       cudaMemcpyHostToDevice));
  checkLastErrorCUDA(__FILE__, __LINE__);

  // Run the kernel...
  threadsPerBlock = 256;

                          cudaMemcpyDeviceToHost));
  REn = cpu_final_REn;
  LJEn = cpu_final_LJEn;

  cudaFree(gpu_pair1);
  cudaFree(gpu_pair2);
