Questions


Topic Replies Views Activity
Report SCF (HF/DFT) Convergence Issues

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…

3 762 November 22, 2024
About the Questions category
0 869 July 1, 2020
Cryptic import_xcfunc warning
3 5 October 2, 2025
Saving SCF Metadynamics Solutions
0 3 October 2, 2025
Question on calculating IPs (cationic states) for L-shell orbitals with IP-EOM-CCSD or ADC(3)
2 20 October 2, 2025
Are there specific command to print the gradient matrix?
6 101 October 2, 2025
Unkown error encountered in a ET coupling calculation using CC2
1 21 October 1, 2025
EOM-CCSD job FOR SINGLET TRIPLET STATE in Q-Chem stuck during SCF convergence
1 23 October 1, 2025
“ADC(3) singlet and triplet excited states with PCM – input and disk quota issues”
1 23 October 1, 2025
How to find the radial shells?
1 28 September 30, 2025
Multiple simultaneous Field_Types?
3 33 September 30, 2025
Different (larger) SCF energy compared to other software (Orca, C4) when using an augmented (aug-cc-pVDZ) basis set
7 67 September 29, 2025
Printing T and R amplitudes in (EOM-)CCSD calculation
2 80 September 28, 2025
QCHEM licence under wsl2 ubuntu system
1 36 September 27, 2025
Too many atoms of one type in orbmat
9 60 September 25, 2025
Large system Hessian crash
2 104 September 24, 2025
Problem oxygen potential energy scan using CCSD(T) and EA state PES using EA-EOM-CCSD
1 82 September 23, 2025
Clarification on RASSCF Calculation of Multiple Spin States in Q-Chem
1 41 September 23, 2025
A question about exploring a transition state
4 159 September 15, 2025
Visualizing Frequencies from Partial Hessians calculation
5 92 September 11, 2025
Pump-probe NEXAFS (TR-XAS)
8 320 September 10, 2025
How to Verify if Optimized SF-TDDFT MECP (Penalty Function) is a True MECP or Artificial?
3 84 September 10, 2025
Which V-coupling value of energy transfer is correct?
6 93 September 4, 2025
Transition (dipole) moment
11 3752 August 29, 2025
Difference between TD-DFT and Internal Stability?
1 118 August 28, 2025
Issues with Slippage in Head-to-Head stacked composites during CDFT optimization
1 140 August 28, 2025
OPE Spectra with solvent
1 100 August 27, 2025
Q-Chem failing to recognize correct symmetry
6 179 August 22, 2025
Enforcing D2h during 2D PES_SCAN for cyclobutadiene
1 109 August 22, 2025
CASSCF frequency crashes in FILE_NUCLEAR_HESSIAN
12 212 August 21, 2025