+ /* For small cut-offs nsp_est will be an underesimate.
+ * With DD nsp_est_nl is an overestimate so nsp_est can get negative.
+ * So to avoid too small or negative nsp_est we set a minimum of
+ * all cells interacting with all 3^3 direct neighbors (3^3-1)/2+1=14.
+ * This might be a slight overestimate for small non-periodic groups of
+ * atoms as will occur for a local domain with DD, but for small
+ * groups of atoms we'll anyhow be limited by nsubpair_target_min,
+ * so this overestimation will not matter.
+ */
+ nsp_est = max(nsp_est, grid->nsubc_tot*14.0);
+