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 1406 November 22, 2024
How to use SGM method to calculate triplet excited states with ROKS?
Questions
3 45 May 3, 2026
Improving the accuracy of CPHF
Questions
1 31 May 1, 2026
New basis set - excited states of Argon
Questions
1 34 April 30, 2026
TDDFT SOC results
Questions
3 98 April 28, 2026
Restarting finite difference frequency jobs
Questions
3 1491 April 28, 2026
Failure in Frequency job
Questions
3 74 April 24, 2026
Webinar 87: Improvements in the OO-DFT user interface
Webinars
0 63 April 23, 2026
Facing convergence issue with CDFT geometry optimization
Questions
1 60 April 22, 2026
Loading basis set from file?
Questions
1 73 April 22, 2026
Non-adiabatic bimolecular reaction dynamics
Questions
5 147 April 18, 2026
Energy inconsistency with PySCF / adcc
Questions
3 127 April 17, 2026
Facing Imaginary frequency in excited state
Questions
1 95 April 17, 2026
Issue with fragment job submission in Q-Chem 5.0.1 EDA calculations
Questions
3 109 April 13, 2026
Crash with NO_REORIENT
Questions
4 139 April 10, 2026
Facing large number of imaginary frequencies in LRC-wPBE functional
Questions
3 124 April 7, 2026
Error in RI-EA-CC2 calculation
Questions
3 149 April 5, 2026
Issue with BR89
Questions
3 135 April 2, 2026
IRC calculation issue
Questions
2 173 April 1, 2026
NAC calculation
Questions
3 204 March 27, 2026
How to generate FCIDump file
Questions
3 153 March 25, 2026
SCF convergence problem in CDFT-CI calculation
Questions
3 193 March 24, 2026
Strange outcome in RAS-SF calculation
Questions
0 137 March 17, 2026
Speeding up ADC(2) calculations
Questions
2 185 March 17, 2026
Is it possible to print gradients of several excited states?
Questions
3 178 March 14, 2026
Memory and RICIS(D) calculations
Questions
4 165 March 11, 2026
MRSF: differences between Q-Chem and OpenQP
Questions
0 213 March 8, 2026
SOC for unrestricted TDDFT
Questions
3 458 March 6, 2026
Gradient and Hessian using CCSD and EOM-CCSD
Questions
3 198 March 5, 2026
Resolution of identity for CDFT?
Questions
6 243 March 3, 2026