My CIS(D) calculation failed due to some memory issue. I try to do a simple sp calculation:
For a small molecule (C8H10), it finished successfully. However, when I tried a larger molecule (C16H18), it failed with the following error:
In TrnAlg: available memory = 155198092
needed mmory = 439204000
Q-Chem fatal error occurred in module 0, line 283:
Insufficient memory for semidirect MP2
It seems that the “available memory” is determined by “MEM_STATIC”, but the maximal value is 2000mb in qchem. Can anyone point me to possible ways to solve this problem? Thank you very much.
There is a known issue that prevents Q-Chem from routing correctly via
METHOD=CIS(D), so the correct input is
Unfortunately this will still die with insufficient
MEM_STATIC. Using RI might help:
I try to use a very big memory, 234000MB. Why did I get this strange error?
Setting up for CIS(D)
SETman timing summary (seconds)
CPU time 16892.57s
System time 0.01s
Wall time 794.71s
Algorithm is semi-direct
Memory given = -401 MB Disk given = 1000000 MB
not enough memory
not enough disk
Both conventional and RI perturbative doubles for CIS use
MEM_STATIC to allocate memory, which is limited to about 8GB. Increasing
MEM_TOTAL will have no effect. If you are running out of memory with conventional (D), try using RI as shown in the comment above. If your job runs out of memory with RI, I recommend contacting firstname.lastname@example.org with your input files for the issue to be resolved in a future version of Q-Chem.