Unexpected ROKS difference density

Hello everyone!

I have been trying to compare how ROKS and TDDFT describe the lowest singlet excited state of a Cu(I) complex. It is well known that the S1 state of such a complex is of MLCT nature. I wanted to compare the difference densities obtained by TDDFT and ROKS methods, and while the TDDFT difference density looks reasonable, the ROKS difference density is somewhat bizarre - both in terms of the shape (the density around copper doesn’t even resemble d orbitals), and the sign (blue colour corresponds to increase in electron density, and red - decrease. Since S1 is MLCT state, the electron density should shift from Cu to the diimine ligand - ROKS difference density suggests the opposite direction).

What could be the reason for such results?

S1 TDDFT difference density:

S1 ROKS difference density:

It would be better to show your Q-Chem input files of two jobs. Especially for S1 ROKS, this is tricky and thus it is important to know whether your calculation is reasonable.

Oh, right, sorry. Here is the input for ROKS job (I’m omitting the $basis section at the end):

$molecule
1 1
C -0.0861094 0.2614760 4.4284010
C 0.5096588 0.3757065 3.1816150
C 1.0496294 1.5837268 2.7359403
C 1.0015825 2.6871167 3.5861737
C 0.4124758 2.5873670 4.8404721
C -0.1333138 1.3783079 5.2546878
O 0.6338685 -0.6873111 2.3114184
C -0.3459637 -1.6608830 2.2800812
C -1.5413836 -1.4062650 1.6026722
C -2.4754908 -2.4388502 1.5126745
C -2.2186179 -3.6821212 2.0770633
C -1.0196214 -3.9120354 2.7408295
C -0.0762404 -2.8967669 2.8442780
P -1.7757750 0.2056633 0.7680290
Cu -0.0099175 1.0374774 -0.4300330
N -0.4956207 2.3714615 -1.9491262
N -0.8717911 3.5984554 -2.0622932
N -0.9896102 3.8322542 -3.3630775
C -0.6887778 2.7479908 -4.1100858
C -0.3648591 1.7919690 -3.1788684
H -1.2783050 4.7547966 -3.6728069
C 0.0612041 0.3934239 -3.2684041
N 0.3547329 -0.1762412 -2.1124075
C 0.7603755 -1.4765272 -2.0871350
C 0.8556498 -2.2408204 -3.2793213
C 0.5337349 -1.6016071 -4.4985454
C 0.1432029 -0.2921021 -4.4993900
C 1.2637142 -3.5940535 -3.1972013
C 1.5636959 -4.1527215 -1.9842185
C 1.4784912 -3.3819513 -0.8021984
C 1.0905607 -2.0705839 -0.8484187
P 1.6202624 1.6680347 1.0064964
H 1.0327142 -1.4617953 0.0513896
H 1.7249879 -3.8376432 0.1562885
H 1.8749591 -5.1949944 -1.9250534
H 1.3340135 -4.1802782 -4.1136924
H 0.6002212 -2.1621707 -5.4315054
H -0.1095659 0.2179378 -5.4271557
H -0.7256958 2.7520097 -5.1932227
H -3.0269040 -0.0460659 0.1565302
H -2.2500413 1.0089958 1.8356931
H 0.8744906 -3.0470020 3.3546538
H -0.8161283 -4.8867822 3.1831365
H -2.9599008 -4.4759748 1.9944196
H -3.4158473 -2.2722399 0.9870773
H 1.4191255 3.6397364 3.2594399
H 0.3785236 3.4572959 5.4948016
H -0.5972867 1.2965012 6.2371540
H -0.5036939 -0.6913384 4.7499609
H 2.8470419 0.9599768 1.0487696
H 2.1497972 2.9800872 0.9947822
$end

$rem
jobtype sp
method camb3lyp
dft_d d3_bj
basis gen
purecart 11
PRINT_GENERAL_BASIS false
gen_scfman false
MAX_SCF_CYCLES 500
SCF_GUESS read
SCF_CONVERGENCE 9
scf_final_print true
MEM_STATIC 2000
MEM_TOTAL 80000
ROKS true
MOLDEN_FORMAT true
IQMOL_FCHK true
plots true
make_cube_files true
$end

$plots
grid_points 200 200 200
total_density 0
$end

TDDFT input:

$molecule
read
$end

$rem
jobtype sp
method camb3lyp
dft_d d3_bj
basis gen
purecart 11
PRINT_GENERAL_BASIS false
gen_scfman false
MAX_SCF_CYCLES 500
SCF_GUESS read
SCF_CONVERGENCE 9
scf_final_print true
MEM_STATIC 2000
MEM_TOTAL 80000
CIS_N_ROOTS 10
CIS_TRIPLETS false
CIS_SINGLETS true
CIS_RELAXED_DENSITY true
RPA false
MOLDEN_FORMAT true
IQMOL_FCHK true
state_analysis true
make_cube_files true
plots true
$end

$plots
grid_points 200 200 200
$end

This is second part if the S1 tddft calculation, in the first part I only generate the GS orbitals in my basis set. The basis set is the same in all my calculations.