Q-Chem Talk

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	1274	November 22, 2024
Resolution of identity for CDFT? Questions	2	7	February 28, 2026
ROHF energy discrepancy between Q-Chem and CFOUR Questions	4	60	February 28, 2026
Optimal settings for large DFT calculations Questions	3	419	February 28, 2026
Using FRAGMO with ptSS-PCM and CDFT for Vertical Electron Transfer Calculation Questions	3	40	February 26, 2026
Geometry Optimization with SS_PCM Questions	1	46	February 25, 2026
Thresh/s2thresh 14? Questions	8	71	February 24, 2026
Normal Modes Question Questions	3	201	February 23, 2026
Symmetry in CCSD(T) frequency calculation Questions	4	81	February 23, 2026
Symmetry of EOM-EA-CCSD. Significance? Questions	1	77	February 21, 2026
Units of vibrational eigenvectors Questions	2	80	February 20, 2026
EOM-EA-CCSD on a Excited state Questions	1	53	February 20, 2026
ROKS emission energy with nonequilibrium solvent Questions	0	54	February 20, 2026
Dyson orbital using EOMCCSDT-IP Questions	1	66	February 20, 2026
Frequency calculation speedup Questions	1	81	February 19, 2026
What is the correct input for the GEOM_OPT_MODE Questions	2	87	February 19, 2026
Large number of imaginary frequencies with ROKS and delta SCF Questions	1	66	February 19, 2026
Ehrenfest Molecular Dynamics Questions	2	64	February 19, 2026
S1 Geom optimization based on TDDFT and delta SCF approach Questions	11	159	February 18, 2026
Q-Chem license on new MacOS How To	0	69	February 17, 2026
Stuck CCSD frequency calculation Questions	2	100	February 16, 2026
Issue with designing functionals Questions	4	70	February 15, 2026
COSMO input file Questions	2	83	February 13, 2026
VQCCD single point calculation issue Questions	0	67	February 13, 2026
RIXS with TDDFT Questions	0	73	February 12, 2026
Wrong multiplicity for large multiplicity element when using projection based embedding Questions	3	81	February 12, 2026
Ground state out of equilibrium calculation Questions	3	145	February 11, 2026
Is it possible to use the NTO-rotated orbitals (for a specific TDDFT state) as the MO set in a subsequent Q-Chem job? Questions	8	285	February 9, 2026
CASSCF with Nonadiabatic Coupling Questions	1	93	February 6, 2026
Complex Scaling on Q-Chem Questions	3	132	February 6, 2026

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…