Hi,
I am computing a lot of molecules for a database following this simple procedure:
- fetch starting geometry (pubchem or chemspider)
- relax with B3LYP
- run CCSD
I occasionally get segmentation faults during B3LYP step. Sometimes switching from pubchem to chemspider geometry solves the problem. Other times it does not work, and I end up relaxing the structure with MP2, which almost always succeeds.
If I use MP2 to relax, I would still do an energy run with B3LYP, just to save energy levels and density.
However, it sometimes happens that B3LYP energy run halts with a segmentation fault, and no other error message.
Here is an example input that causes the problem, geometry was relaxed with MP2:
import psi4
import numpypsi4.set_memory(‘16 GB’) # tried 24 GB too
mol = psi4.geometry("""
units ang
symmetry c1
O 1.730188188193 0.147134170472 -1.541079571468
O -1.972430673095 1.400015800140 -1.061946749537
O -0.781339312812 -2.021576227936 0.604416105325
O 1.672063999896 -0.277249340562 0.631609932786
O -0.092131489300 2.178597970266 -0.188517688713
O -1.355983244818 -0.092340668662 1.527263395006
N 1.172565423737 -0.093180910450 -0.473730503089
N -0.831554065574 1.298925478150 -0.618838469965
N -0.889102361362 -0.799081785244 0.639635167804
C -0.325193558978 -0.112529063318 -0.570391259620
H -0.630663110642 -0.646728415742 -1.474001655305
“”")mol.fix_com(True)
mol.fix_orientation(True)psi4.set_options({‘basis’: ‘cc-pvdz’})
psi4.set_options({‘cachelevel’: 0}) # tried 0,1,2… all failed
psi4.set_options({‘reference’: ‘rhf’})
psi4.set_options({‘DF_SCF_GUESS’: ‘false’}) # tried both
psi4.set_options({‘scf_type’: ‘out_of_core’}) # tried all!
E, wf = psi4.energy(‘B3LYP’, molecule=mol, return_wfn=True)
The output stops here:
==> Integral Setup <==
==> DiskJK: Disk-Based J/K Matrices <==
J tasked: Yes K tasked: Yes wK tasked: No Memory [MiB]: 10706 Schwarz Cutoff: 1E-12
Even with the other scf_type, or guess type, the calculation does not get past the integral setup.
HF and MP2 calculations give no troubles with this structure. The code was compiled from source, version 1.3a2.dev362, and 1.3a2.dev402
Any idea about what is going on and how to fix it?