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	1233	November 22, 2024
Ground state out of equilibrium calculation Questions	3	74	February 11, 2026
wrong multiplicity for large multiplicity element when using projection based embedding Questions	0	17	February 10, 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	219	February 9, 2026
CASSCF with Nonadiabatic Coupling Questions	1	45	February 6, 2026
Complex Scaling on Q-Chem Questions	3	60	February 6, 2026
SOC for Diabatic-State-Based Methods Questions	3	64	February 2, 2026
SOC for unrestricted TDDFT Questions	2	91	January 30, 2026
Visualization/export of SF-TDDFT orbitals Questions	5	140	January 27, 2026
Error while running frequency calculation Questions	4	87	January 27, 2026
Frozen atoms move during optimization Questions	2	89	January 27, 2026
Truncation of non-bonded interactions in QM/MM Questions	1	68	January 26, 2026
Webinar 85: XCIS-CVS: Core-level Spectroscopy in Q-Chem Webinars	0	74	January 23, 2026
How to read saved scratch file for hessian How To	1	81	January 22, 2026
Issue with FRAGMO Optimization: Structural Distortion Questions	1	83	January 20, 2026
MRSF Transition dipole moment Questions	2	94	January 20, 2026
Single Na ion calculation using MP2 Questions	2	102	January 16, 2026
Using SF-TDDFT single-point energies for TS optimized at DFT level Questions	1	103	January 13, 2026
Which value to choose when calculating SOC? Questions	3	112	January 13, 2026
Energy conservation problems during dynamics , bond breaking and forming for collision reaction Questions	1	98	January 11, 2026
Trouble using EOM-CCSD, with frozen core Questions	9	285	January 9, 2026
$reorder_mo not affecting beta orbitals as expected Questions	4	143	January 9, 2026
Conceptual question regarding the applicability of SF-TDDFT method Questions	1	132	January 9, 2026
Error in EDA 2 calculation Questions	2	107	January 9, 2026
ALMO_EDA job failure Questions	1	116	January 9, 2026
Qchem randomly aborting Questions	3	121	January 7, 2026
How to work with intermolecular distance? How To	1	124	January 5, 2026
How to define intermolecular distance and charge between two molecule? How To	3	184	January 3, 2026
Normal Modes Question Questions	1	114	January 2, 2026
Facing issue with spin-contamination Questions	1	157	December 29, 2025

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…