Dear, Q-chem users
I am studying excited states, through TD-DFT formalism. I am interested in using AIMAll suite to analyze the wave function of a specific excited state. For this purpose, I have been using the molden file as printed by q-chem, but I always obtain de molden orbitals for the ground state.
Is there a way to print molden, fchk or wfn files for a specific excited state?
I thank your time
Best regards
My input file for benzene molecule
$molecule
0 1
C 0.1766025298 -1.3831100418 -0.0000642602
C -1.1091486613 -0.8440392726 -0.0001325799
C -1.2861943091 0.5388740599 -0.0001524743
C -0.1765396408 1.3830970879 -0.0000775712
C 1.1091181584 0.8440650085 -0.0000023315
C 1.2861764727 -0.5389479950 0.0000002187
H 0.3133148820 -2.4587719400 -0.0000464700
H -1.9716043687 -1.5011053407 -0.0001973857
H -2.2863850353 0.9573098384 -0.0001980363
H -0.3133962125 2.4587405110 -0.0000961451
H 1.9716586458 1.5010201848 0.0000613166
H 2.2864215648 -0.9572534823 0.0000436208
$end
$rem
! JOBTYPE = FORCE
BASIS = 6-311++G(2d,2p)
METHOD = t-HCTHh
CIS_N_ROOTS = 4
CIS_SINGLETS = true
CIS_TRIPLETS = true
print_orbitals = true
CIS_STATE_DERIV = 1
RPA = 2
$end
@@@
$molecule
read
$end
$rem
! SCF_GUESS = READ
JOBTYPE = FORCE
BASIS = 6-311++G(2d,2p)
METHOD = t-HCTHh
molden_format = true
WRITE_WFN = bn-T1
IQMOL_FCHK = true
CIS_STATE_DERIV = 1
CIS_N_ROOTS = 4
CIS_SINGLETS = true
CIS_TRIPLETS = true
PRINT_GENERAL_BASIS=TRUE
PRINT_ORBITALS=TRUE
SCF_FINAL_PRINT=2
$end
There is a way. Listed below is a sample job from the manual. The Molden-formatted files (one per state, since the NTO are state-specific) are deposited in a sub-directory called “NTOs” in the job’s scratch directory, which means that you need to be sure to save the scratch files. Run Q-Chem with a command that is something like
qchem -save input.in output.out scratchname
and then find the $QCSCRATCH/scratchname/NTOs. There are files called, e.g., TDA.singlet.1 (first singlet state for the Tamm-Dancoff calculation, could also be RPA instead of TDA if you ran both calculations). Next state is TDA.singlet.2, etc.
$comment
uracil excited states; generate NTOs
$end
$molecule
0 1
N -2.181263 0.068208 0.000000
C -2.927088 -1.059037 0.000000
N -4.320029 -0.911094 0.000000
C -4.926706 0.301204 0.000000
C -4.185901 1.435062 0.000000
C -2.754591 1.274555 0.000000
N -1.954845 2.338369 0.000000
H -0.923072 2.224557 0.000000
H -2.343008 3.268581 0.000000
H -4.649401 2.414197 0.000000
H -6.012020 0.301371 0.000000
H -4.855603 -1.768832 0.000000
O -2.458932 -2.200499 0.000000
$end
$rem
METHOD B3LYP
BASIS 6-31+G*
CIS_N_ROOTS 3
NTO_PAIRS 2
$end
Jherbert, Thank you for your valuable response,
I tried to analyze the TDA.x.n and RPA.x.n files but they are not useful for me, because they are not counting all the electrons and orbitals for construct a wave function of the excited state.
With this in mind, I was able to obtain the Natural Orbitals, e.g. T_1_no.mo, gs_no.mo, printed in the $plots directory. These orbitals are completed but I faced another issue: when I convert these molden files to a .wfx file using molden2aim, the code shows me
Warning: the total electron is different from the sum of occupations!
#Electron = 42.0000
Sum_Occupation = 20.0000
#Core Electron = 0.0000
Net Charge = 22.0000
For the benzene molecule.
Reviewing the molden file printed by qchem I find, besides that beta MOs of R-/RO-SCF are not printed, the occupations number is also incorrect.
Lastly, I edited the *.mo files to adjust the occupation numbers, I just change Occup=0 to Occup=1 in the next empty orbital.
With this edited file, I proceed to convert it to .wfx and integrate the wave function file in AIMALL but I obtain the same atomic properties for the Ground State and Excited states wave functions, so there is something wrong in the .mo files.
Do you know a way to print the complete molecular orbitals for specific excited states?
Is this error common in molden files printed by q-chem?
P.S. I also tried Unrestricted calcs but no luck.
Best regards
I am not 100% sure that I understand your question. Typically we use the NTOs just for visualization purposes. The number of them that is printed is controlled via NTO_PAIRS. For the occupancies, check whether you are off by a square root. Eigenvalues of the difference density matrix (Delta P) are the squares of the singular values of X (TDA) or X+Y (RPA).
I am not familiar with AIMALL.
Jherbert,
I am sorry, the problem is simple: the orbitals printed in T_1_no.mo are the same as GS orbitals, not of the T1 Excited State.
And also the occupation of these orbitals saved in $plots is incorrect, now I know that is a bug in q-chem.
molden2aim output:
** WARNING ***
There is a BUG in Q-Chem RO-SCF. In this case,
please correct the occupation numbers of singly occupied MOs manually.
Well, do you know a way to fix my any of these problems?
Thank you!
Short answer to 2nd problem is ‘no’. I’m not familiar with ‘molden2aim’ (at all) so I don’t know how to help with that. For the first part, I’ve been trying (failing) to find some time to look into this, but it seems like you may have found a bug. The best way to get it looked into is to submit a bug report to Q-Chem support (see here for contact info: https://www.q-chem.com/about/contact). Describe the problem and send a sample input/output that illustrates it. They will create a ticket and someone (maybe me) will try to look into it.
Thanks in advance. -John