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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…

3 775 November 22, 2024
Question on calculating IPs (cationic states) for L-shell orbitals with IP-EOM-CCSD or ADC(3)
Questions
13 72 October 8, 2025
EOMCCSDT calculations
How To
3 97 October 8, 2025
SCF convergence issue with diffuse functions on basis set
Questions
12 59 October 8, 2025
Single Point immediately fails with DM alg and AUTOSAD guess
Questions
4 32 October 8, 2025
Keywords for printing <S^2> values using unrestricted TDDFT (RPA=2)
Questions
2 169 October 7, 2025
Clarification on RASSCF Calculation of Multiple Spin States in Q-Chem
Questions
2 66 October 6, 2025
Cryptic import_xcfunc warning
Questions
8 57 October 4, 2025
Fchk file size increased with Q-Chem 6.1?
Questions
4 524 October 3, 2025
Irreducible representation of electrons
How To
1 38 October 3, 2025
Saving SCF Metadynamics Solutions
Questions
0 42 October 2, 2025
Are there specific command to print the gradient matrix?
Questions
6 120 October 2, 2025
Unkown error encountered in a ET coupling calculation using CC2
Questions
1 58 October 1, 2025
EOM-CCSD job FOR SINGLET TRIPLET STATE in Q-Chem stuck during SCF convergence
Questions
1 54 October 1, 2025
“ADC(3) singlet and triplet excited states with PCM – input and disk quota issues”
Questions
1 49 October 1, 2025
How to find the radial shells?
Questions
1 50 September 30, 2025
Multiple simultaneous Field_Types?
Questions
3 55 September 30, 2025
Different (larger) SCF energy compared to other software (Orca, C4) when using an augmented (aug-cc-pVDZ) basis set
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7 89 September 29, 2025
Printing T and R amplitudes in (EOM-)CCSD calculation
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2 103 September 28, 2025
QCHEM licence under wsl2 ubuntu system
Questions
1 57 September 27, 2025
Too many atoms of one type in orbmat
Questions
9 78 September 25, 2025
Fuller context of error messages
How To
1 75 September 24, 2025
Large system Hessian crash
Questions
2 119 September 24, 2025
Problem oxygen potential energy scan using CCSD(T) and EA state PES using EA-EOM-CCSD
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1 97 September 23, 2025
A question about exploring a transition state
Questions
4 176 September 15, 2025
Visualizing Frequencies from Partial Hessians calculation
Questions
5 102 September 11, 2025
Pump-probe NEXAFS (TR-XAS)
Questions
8 337 September 10, 2025
How to Verify if Optimized SF-TDDFT MECP (Penalty Function) is a True MECP or Artificial?
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3 100 September 10, 2025
Which V-coupling value of energy transfer is correct?
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6 109 September 4, 2025
Transition (dipole) moment
Questions
11 3783 August 29, 2025