Quicklinks in Video: (Links to slides and inputs appear after this Quicklink section)
1:51 Core-level spectroscopy - introduction and outline
6:11 Challenges
7:44 Methods for core-level states
8:52 Koopmans' theorem
10:53 XES by Koopmans' theorem
11:37 Example: XES with src1r1
12:36 Koopmans' theorem with FON
13:45 State-specific methods (Delta-E) based on MOM algorithm
14:37 Maximum Overlap Method
17:20 MOM for core states
19:38 TDDFT Calculations using CVS or MOM reference
20:09 MOM and TDDFT - Example: Calculation of water XES by TD-DFT
21:45 TDDFT and TRNSS - Example: Calculation of water XAS by TD-DFT with TRNSS
23:23 TDDFT and TRNSS - recommendation
23:52 Correlated methods with core-valence separation: CVS-EOM-CC and CVS-ADC
24:04 Correlated methods
24:33 Correlated methods for excited states and ionized states
27:51 Problems with core states
28:56 Problem with continuum
30:37 Core-valence separation
33:04 CVS-EOM and CVS-ADC
34:20 fc-CVS-EOM-CC methods
35:48 CVS-EOM-CC methods - Available features
37:46 Examples
39:23 Examples: XAS
41:08 XAS - How to deploy
42:29 Examples: XES
43:33 XES - How to deploy
45:00 Example: RIXS
46:42 RIXS - How to deploy
48:29 Tricks-of-the-trade
51:04 Transient XAS-XPS
53:22 TR-XPS example
54:50 CVS-EOM-CC - Wrap up
55:32 Basis sets for core states
56:45 Conclusion
57:09 Thanks
58:51 Further reading
59:42 Learning about Q-Chem
Question & Answers
1:00:22 Q&A - How reliable is the TDDFT method for core-excitation spectroscopy when we have more than one core orbitals?
1:01:25 Q&A - Is there a rationale to choose the shifting of spectra by 0.3 to 1eV? Why do we have an offset?
1:02:44 Q&A - Is there a script or option in Q-Chem to plot the excitation spectra from transition energies and intensities?
1:03:29 Q&A - What is the limit for the total number of electrons/basis functions for CVS-EOM-CCSD for computing XAS spectra? Would this work for transition metal ion complexes?
1:05:20 Q&A - Is the CVS-EOM-CCSD method applicable for the L3 edge XAS?
1:06:46 Q&A - How accurate are the EOM-CCSD methods for core-excited or ionized states of systems containing metals?
1:08:13 Q&A - Why can we freeze the core orbitals and still get an accurate result (such as for C, N, O example)? Shouldn't we consider all orbital relaxation effects?
1:10:51 You have mentioned EOM-MP2 in the beginning; have you benchmarked it for CVS applications?
Slides from this presentation can be found at [ Ссылка ]
Inputs can be found at [ Ссылка ]
Please note the following:
1. Features in the input file, benzene_peakA_10st.in, will be available in the upcoming release. Computing this input file with Q-Chem 5.2.1 or lower will result in the following error message.
“CC_EOM_RIXS 5
The $rem variable is recognized but its requested value "5" is not”
2. We recommend all coupled-cluster jobs should run with appropriate CC_MEMORY setting, at least 8000 (8GB), but preferably 16 GB, and in parallel, so they are not too slow.
