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--- exercises:2017_uzh_cp2k-tutorial:gw [2017/07/04 07:57] – [5. Cubic-scaling GW calculations] jwilhelm
+++ exercises:2017_uzh_cp2k-tutorial:gw [2017/07/04 08:00] – [5. Cubic-scaling GW calculations] jwilhelm
@@ Line 316: / Line 316: @@
           ! in imag. time and frequency
           MINIMAX
-          ! If the HOMO-LUMO gap of the system is small, more
+          ! If the HOMO-LUMO gap of the system is small, 20
-          ! points for the time/frequency grid have to be used
+          ! points for the time/frequency grid should be used
           ! (flag RPA_NUM_QUAD_POINTS). The time and frequency grid
           ! are equally large. The maximum grid size is 20.
-          ! In principle, the grid size is a convergence parameter
+          ! For large-gap systems (as the water molecule), 12 points
-          ! but for many large-gap systems (as the water molecule),
+          ! should be sufficient
-          ! convergence of this grid is hard to achieve due to
-          ! numerical instabilities.
           RPA_NUM_QUAD_POINTS  12
           ! imaginary time flag enables cubic-scaling RPA or
@@ Line 330: / Line 328: @@
           &IM_TIME
             EPS_FILTER_IM_TIME 1.0E-12
-            ! for large systems, increase GROUP_SIZE_3C not
+            ! for large systems, increase GROUP_SIZE_3C
-            ! to run out of memory (OOM)
+            ! to prevent out of memory (OOM)
             GROUP_SIZE_3C 1
             ! for extremely large systems, increase GROUP_SIZE_P
-            ! not to run OOM
+            ! to prevent OOM
             ! for very large systems, it is also recommended
-            ! to use OMP threads not to run OOM
+            ! to use OMP threads to prevent OOM
             GROUP_SIZE_P 1
             GW