Questions

Topic	Replies	Views	Activity
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…	3	813	November 22, 2024
About the Questions category	0	888	July 1, 2020
SCF convergence issue with diffuse functions on basis set	27	202	October 22, 2025
Unexpected behaviour: core orbitals are not frozen during MP2/MP3 step in ADC calculations	3	27	October 22, 2025
Problem oxygen potential energy scan using CCSD(T) and EA state PES using EA-EOM-CCSD	8	184	October 22, 2025
Crash upon frequency calculations with range separated bybrid	1	32	October 21, 2025
Cryptic import_xcfunc warning	10	109	October 20, 2025
What sort of RI techniques are safe to use with different types of SCF?	3	66	October 16, 2025
RI worsens SCF timings	4	74	October 16, 2025
Question on calculating IPs (cationic states) for L-shell orbitals with IP-EOM-CCSD or ADC(3)	14	137	October 9, 2025
Is CVS approximation available for IP-ADC(3)?	0	61	October 9, 2025
Single Point immediately fails with DM alg and AUTOSAD guess	4	89	October 8, 2025
Keywords for printing <S^2> values using unrestricted TDDFT (RPA=2)	2	212	October 7, 2025
Clarification on RASSCF Calculation of Multiple Spin States in Q-Chem	2	99	October 6, 2025
Fchk file size increased with Q-Chem 6.1?	4	554	October 3, 2025
Saving SCF Metadynamics Solutions	0	72	October 2, 2025
Are there specific command to print the gradient matrix?	6	149	October 2, 2025
Unkown error encountered in a ET coupling calculation using CC2	1	98	October 1, 2025
EOM-CCSD job FOR SINGLET TRIPLET STATE in Q-Chem stuck during SCF convergence	1	94	October 1, 2025
“ADC(3) singlet and triplet excited states with PCM – input and disk quota issues”	1	82	October 1, 2025
How to find the radial shells?	1	73	September 30, 2025
Multiple simultaneous Field_Types?	3	82	September 30, 2025
Different (larger) SCF energy compared to other software (Orca, C4) when using an augmented (aug-cc-pVDZ) basis set	7	127	September 29, 2025
Printing T and R amplitudes in (EOM-)CCSD calculation	2	137	September 28, 2025
QCHEM licence under wsl2 ubuntu system	1	78	September 27, 2025
Too many atoms of one type in orbmat	9	101	September 25, 2025
Large system Hessian crash	2	146	September 24, 2025
A question about exploring a transition state	4	215	September 15, 2025
Visualizing Frequencies from Partial Hessians calculation	5	125	September 11, 2025
Pump-probe NEXAFS (TR-XAS)	8	379	September 10, 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…