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	1258	November 22, 2024
Normal Modes Question Questions	3	173	February 23, 2026
Thresh/s2thresh 14? Questions	5	27	February 23, 2026
Symmetry in CCSD(T) frequency calculation Questions	4	48	February 23, 2026
Symmetry of EOM-EA-CCSD. Significance? Questions	1	53	February 21, 2026
Units of vibrational eigenvectors Questions	2	49	February 20, 2026
EOM-EA-CCSD on a Excited state Questions	1	31	February 20, 2026
ROKS emission energy with nonequilibrium solvent Questions	0	32	February 20, 2026
Dyson orbital using EOMCCSDT-IP Questions	1	41	February 20, 2026
Frequency calculation speedup Questions	1	48	February 19, 2026
What is the correct input for the GEOM_OPT_MODE Questions	2	66	February 19, 2026
Large number of imaginary frequencies with ROKS and delta SCF Questions	1	43	February 19, 2026
Ehrenfest Molecular Dynamics Questions	2	46	February 19, 2026
S1 Geom optimization based on TDDFT and delta SCF approach Questions	11	133	February 18, 2026
Q-Chem license on new MacOS How To	0	48	February 17, 2026
Stuck CCSD frequency calculation Questions	2	84	February 16, 2026
Issue with designing functionals Questions	4	57	February 15, 2026
COSMO input file Questions	2	65	February 13, 2026
VQCCD single point calculation issue Questions	0	54	February 13, 2026
RIXS with TDDFT Questions	0	59	February 12, 2026
Wrong multiplicity for large multiplicity element when using projection based embedding Questions	3	66	February 12, 2026
Ground state out of equilibrium calculation Questions	3	123	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	265	February 9, 2026
CASSCF with Nonadiabatic Coupling Questions	1	80	February 6, 2026
Complex Scaling on Q-Chem Questions	3	104	February 6, 2026
SOC for Diabatic-State-Based Methods Questions	3	114	February 2, 2026
SOC for unrestricted TDDFT Questions	2	137	January 30, 2026
Visualization/export of SF-TDDFT orbitals Questions	5	186	January 27, 2026
Error while running frequency calculation Questions	4	126	January 27, 2026
Frozen atoms move during optimization Questions	2	132	January 27, 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…