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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…

3 895 November 22, 2024
Second Derivative
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TSVDW and MBD crashes
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4 145 October 27, 2025
SCF convergence issue with diffuse functions on basis set
Questions
27 330 October 22, 2025
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Questions
8 293 October 22, 2025
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Questions
1 125 October 21, 2025
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Questions
10 201 October 20, 2025
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Questions
3 152 October 16, 2025
RI worsens SCF timings
Questions
4 166 October 16, 2025
EOMCCSDT calculations
How To
2 228 September 29, 2025
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Questions
14 219 October 9, 2025
Is CVS approximation available for IP-ADC(3)?
Questions
0 140 October 9, 2025
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Questions
4 172 October 8, 2025
Keywords for printing <S^2> values using unrestricted TDDFT (RPA=2)
Questions
2 299 October 7, 2025
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Questions
2 187 October 6, 2025
Fchk file size increased with Q-Chem 6.1?
Questions
4 642 October 3, 2025
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How To
1 149 October 3, 2025
Saving SCF Metadynamics Solutions
Questions
0 157 October 2, 2025
Are there specific command to print the gradient matrix?
Questions
6 246 October 2, 2025
Unkown error encountered in a ET coupling calculation using CC2
Questions
1 189 October 1, 2025
EOM-CCSD job FOR SINGLET TRIPLET STATE in Q-Chem stuck during SCF convergence
Questions
1 254 October 1, 2025
“ADC(3) singlet and triplet excited states with PCM – input and disk quota issues”
Questions
1 166 October 1, 2025
How to find the radial shells?
Questions
1 154 September 30, 2025
Multiple simultaneous Field_Types?
Questions
3 162 September 30, 2025
Different (larger) SCF energy compared to other software (Orca, C4) when using an augmented (aug-cc-pVDZ) basis set
Questions
7 223 September 29, 2025
Printing T and R amplitudes in (EOM-)CCSD calculation
Questions
2 296 September 28, 2025
QCHEM licence under wsl2 ubuntu system
Questions
1 157 September 27, 2025
Too many atoms of one type in orbmat
Questions
9 187 September 25, 2025