Topic Replies Views Activity
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 1424 November 22, 2024
aug-cc-pV5Z with external charges
Questions
1 18 May 12, 2026
CDFT block set up
How To
1 53 May 7, 2026
New basis set - excited states of Argon
Questions
3 76 May 5, 2026
PES scan not respecting mem_total
Questions
6 67 May 4, 2026
How to use SGM method to calculate triplet excited states with ROKS?
Questions
3 73 May 3, 2026
Improving the accuracy of CPHF
Questions
1 56 May 1, 2026
TDDFT SOC results
Questions
3 139 April 28, 2026
Restarting finite difference frequency jobs
Questions
3 1517 April 28, 2026
Failure in Frequency job
Questions
3 98 April 24, 2026
Webinar 87: Improvements in the OO-DFT user interface
Webinars
0 92 April 23, 2026
Facing convergence issue with CDFT geometry optimization
Questions
1 86 April 22, 2026
Loading basis set from file?
Questions
1 101 April 22, 2026
Non-adiabatic bimolecular reaction dynamics
Questions
5 168 April 18, 2026
Energy inconsistency with PySCF / adcc
Questions
3 159 April 17, 2026
Facing Imaginary frequency in excited state
Questions
1 118 April 17, 2026
Issue with fragment job submission in Q-Chem 5.0.1 EDA calculations
Questions
3 129 April 13, 2026
Crash with NO_REORIENT
Questions
4 161 April 10, 2026
Facing large number of imaginary frequencies in LRC-wPBE functional
Questions
3 146 April 7, 2026
Error in RI-EA-CC2 calculation
Questions
3 175 April 5, 2026
Issue with BR89
Questions
3 159 April 2, 2026
IRC calculation issue
Questions
2 198 April 1, 2026
NAC calculation
Questions
3 229 March 27, 2026
How to generate FCIDump file
Questions
3 176 March 25, 2026
SCF convergence problem in CDFT-CI calculation
Questions
3 221 March 24, 2026
Strange outcome in RAS-SF calculation
Questions
0 158 March 17, 2026
Speeding up ADC(2) calculations
Questions
2 212 March 17, 2026
Is it possible to print gradients of several excited states?
Questions
3 196 March 14, 2026
Memory and RICIS(D) calculations
Questions
4 187 March 11, 2026
MRSF: differences between Q-Chem and OpenQP
Questions
0 242 March 8, 2026