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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 1390 November 22, 2024
Facing convergence issue with CDFT geometry optimization
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1 20 April 22, 2026
TDDFT SOC results
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0 21 April 22, 2026
Loading basis set from file?
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Non-adiabatic bimolecular reaction dynamics
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5 105 April 18, 2026
Energy inconsistency with PySCF / adcc
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3 93 April 17, 2026
Facing Imaginary frequency in excited state
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1 65 April 17, 2026
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3 84 April 13, 2026
Crash with NO_REORIENT
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4 103 April 10, 2026
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3 87 April 7, 2026
Error in RI-EA-CC2 calculation
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3 110 April 5, 2026
Issue with BR89
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3 97 April 2, 2026
IRC calculation issue
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2 134 April 1, 2026
NAC calculation
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3 161 March 27, 2026
How to generate FCIDump file
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3 124 March 25, 2026
SCF convergence problem in CDFT-CI calculation
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3 157 March 24, 2026
Strange outcome in RAS-SF calculation
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0 111 March 17, 2026
Speeding up ADC(2) calculations
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2 153 March 17, 2026
Is it possible to print gradients of several excited states?
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3 148 March 14, 2026
Memory and RICIS(D) calculations
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4 136 March 11, 2026
MRSF: differences between Q-Chem and OpenQP
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0 170 March 8, 2026
SOC for unrestricted TDDFT
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3 407 March 6, 2026
Gradient and Hessian using CCSD and EOM-CCSD
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3 164 March 5, 2026
Resolution of identity for CDFT?
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6 197 March 3, 2026
ROHF energy discrepancy between Q-Chem and CFOUR
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4 221 February 28, 2026
Optimal settings for large DFT calculations
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3 549 February 28, 2026
Using FRAGMO with ptSS-PCM and CDFT for Vertical Electron Transfer Calculation
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3 161 February 26, 2026
Geometry Optimization with SS_PCM
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1 191 February 25, 2026
Thresh/s2thresh 14?
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8 226 February 24, 2026
Normal Modes Question
Questions
3 376 February 23, 2026