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Report SCF (HF/DFT) Convergence Issues
Questions

Dear Q-Chem Community, If you have any SCF (HF/DFT) jobs that are time-consuming or are facing convergence difficulties with Q-Chem, please send them to support@q-chem.com with the subject line “SCF Convergence Issue” t…

3 1712 November 22, 2024
Frequency calculation stalls during CPSCF/CPCM-SWIG Hessian step
Questions
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Spherical or Cartesian
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4 64 August 26, 2026
r2scan very slow (not scf but doing extra calculations)
How To
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Q-Chem Webinar 89: M-Chem
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3 634 August 10, 2026
BSSE error input file
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0 131 August 5, 2026
Webinar 88: What's new in Q-Chem 7
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CDFT-CI convergence issue
Questions
1 183 July 26, 2026
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Questions
1 205 July 24, 2026
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1 918 March 12, 2023
Some doubt regarding CAP onset
Questions
3 230 July 6, 2026
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Questions
0 200 June 30, 2026
Unexpected Energy Ordering in TDDFT Nonequilibrium PCM
Questions
1 226 June 24, 2026
Amber force field generation
Questions
3 305 June 23, 2026
What sort of SCF calculations are supported with external fields?
Questions
5 318 June 16, 2026
CDFT-CI Coupling convergence issue
Questions
5 320 June 15, 2026
ALMO-EDA/COVP SCF Convergence Failure for Open-Shell Anion Radical System
Questions
6 421 June 13, 2026
Lowering amplitude threshold when doing eom CCSD job
Questions
0 230 June 11, 2026
Error in RI-EA-CC2 calculation
Questions
4 495 June 7, 2026
FCIDUMP support
Questions
1 262 June 5, 2026
Upgrade to DFT-D4 in QChem 6.4
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1 294 June 4, 2026
Electronic structures of TDDFT-1D states
Questions
0 275 June 2, 2026
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1 295 May 29, 2026
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How To
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Questions
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Restarting finite difference frequency jobs
Questions
4 1829 May 18, 2026