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	1346	November 22, 2024
NAC calculation Questions	3	78	March 27, 2026
How to generate FCIDump file Questions	3	53	March 25, 2026
SCF convergence problem in CDFT-CI calculation Questions	3	86	March 24, 2026
Strange outcome in RAS-SF calculation Questions	0	52	March 17, 2026
Speeding up ADC(2) calculations Questions	2	88	March 17, 2026
Is it possible to print gradients of several excited states? Questions	3	96	March 14, 2026
Memory and RICIS(D) calculations Questions	4	78	March 11, 2026
MRSF: differences between Q-Chem and OpenQP Questions	0	99	March 8, 2026
SOC for unrestricted TDDFT Questions	3	288	March 6, 2026
Gradient and Hessian using CCSD and EOM-CCSD Questions	3	103	March 5, 2026
Resolution of identity for CDFT? Questions	6	134	March 3, 2026
ROHF energy discrepancy between Q-Chem and CFOUR Questions	4	161	February 28, 2026
Optimal settings for large DFT calculations Questions	3	503	February 28, 2026
Using FRAGMO with ptSS-PCM and CDFT for Vertical Electron Transfer Calculation Questions	3	106	February 26, 2026
Geometry Optimization with SS_PCM Questions	1	126	February 25, 2026
Thresh/s2thresh 14? Questions	8	141	February 24, 2026
Normal Modes Question Questions	3	285	February 23, 2026
Symmetry in CCSD(T) frequency calculation Questions	4	153	February 23, 2026
Symmetry of EOM-EA-CCSD. Significance? Questions	1	158	February 21, 2026
Units of vibrational eigenvectors Questions	2	192	February 20, 2026
EOM-EA-CCSD on a Excited state Questions	1	128	February 20, 2026
ROKS emission energy with nonequilibrium solvent Questions	0	118	February 20, 2026
Dyson orbital using EOMCCSDT-IP Questions	1	153	February 20, 2026
Frequency calculation speedup Questions	1	274	February 19, 2026
What is the correct input for the GEOM_OPT_MODE Questions	2	167	February 19, 2026
Large number of imaginary frequencies with ROKS and delta SCF Questions	1	128	February 19, 2026
Ehrenfest Molecular Dynamics Questions	2	144	February 19, 2026
S1 Geom optimization based on TDDFT and delta SCF approach Questions	11	233	February 18, 2026
Q-Chem license on new MacOS How To	0	155	February 17, 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…