Update README.md for QE

quantum_espresso/README.md

@@ -236,7 +236,7 @@ since it allows rapid testing of the QE installation, but for benchmark purposes
 |------------|---------------|-------------|----------|------|
 | test case A (small) | AUSURF | 112 atoms | 2 | < 4-8 nodes on most systems |
 | test case C (medium)| GRIR443 | 432 | 4| Medium scaling, often 20 nodes |
-| test case B (large) | CNT | Carbon nanotube | | Large scaling runs only. Memory and time requirements very high|
+| test case B (large) | CNT | Carbon nanotube |1| Large scaling runs only. Memory and time requirements very high|
 
 
 __Last updated: 22-October-2020__