Regarding Antiferromagnetically coupled states in DODFT

Questions
#1

Dear Developers,

Is it possible to define the spin of two metal centers antiferromagnetically (AF) while performing FODFT? In the below given input, in fragment 1, I need to couple Fe1 and Fe2 antiferromagnetically as High spin species. if both Fe centers are Fe(II), Fe1 should have spin 4/2 and Fe2 should have spin of -4/2.
Running the below given input, I am getting the spin pop at two Fe centers of 0.0.
I tried using a guess from a desired AF coupled state but it didn’t work. I am using Q-Chem 6.0

Input:

$molecule
-4 6
--
-4 1
Fe      38.023885616     56.233184616     31.861758384
Fe      39.207127383     53.848074981     32.773074228
S       40.224277784     55.715911618     31.922609451
S       37.032520884     54.392925474     32.692871647
S       37.264261755     56.681703756     29.601931339
S       39.983077803     51.895802400     31.515205906
S       39.981210049     53.263357615     34.920025561
S       37.409795075     58.223687870     33.131434124
H       36.067134933     57.236158825     29.558723144
H       40.915391546     52.296804381     30.671174807
H       41.287728240     53.388547046     35.060516922
H       37.289586636     59.341197402     32.439247459
--
0 6
Fe      38.955586339     48.774013996     37.229550837
N       38.542155163     50.685031609     37.955633360
N       36.989922997     48.277432713     37.756246820
N       40.957670701     49.146201726     37.723189783
N       39.402644545     46.748857825     37.427305456
C       39.446420989     51.714282750     38.099797287
C       36.419479968     47.030155517     37.652416813
C       37.293221626     51.242024202     38.122137995
C       35.953150466     49.160249251     37.949277236
C       41.531961480     50.383589099     37.898282645
C       38.501569829     45.709773819     37.363146474
C       41.996546497     48.252118196     37.610191733
C       40.654268259     46.180763521     37.349358596
C       38.747404706     52.950897173     38.342388290
C       34.986401282     47.130357850     37.791078483
C       37.415272425     52.658696381     38.356462546
C       34.697670702     48.448757777     37.975154646
C       42.970305372     50.263805004     37.903284535
C       39.204436157     44.458680115     37.227446849
C       43.257808001     48.944409582     37.724951845
C       40.536451033     44.750060465     37.219212924
H       39.223997324     53.910207351     38.494656008
H       34.302393992     46.292867850     37.755594946
H       36.584095461     53.331174192     38.522394404
H       33.729441404     48.909108610     38.120635710
H       43.658554609     51.088556113     38.032280858
H       38.730876585     43.488333977     37.159095414
H       44.229146110     48.470232853     37.678318789
H       41.371064984     44.065915581     37.142590802
C       40.831802789     51.575793183     38.060523463
C       37.118485343     45.842041653     37.457713650
C       41.856608811     46.879423614     37.425067630
C       36.092437831     50.536363394     38.107265054
H       41.419896311     52.478829369     38.189399474
H       36.532010596     44.931240145     37.391716222
H       42.769369848     46.297188357     37.349451058
H       35.182789978     51.110454373     38.251823098
S       38.891098489     48.977062980     34.923064638
H       38.508304728     50.269664593     34.864992034
$end

$rem
  jobtype sp
  method  B3LYP
  basis   cc-pvdz-full
  unrestricted true
  Becke_shift Unshifted
  scf_convergence 6
  Mem_total 80000
  mem_static 9600
  symmetry false
  sym_ignore true
  frag_diabat_method fodft
  fodft_method 1
$end
#2

Could you please post snippets of your output too, so non-experts like me can better understand your query? I might be wrong, but I don’t think you can constrain specific spins on individual metal centers within a fragment with FODFT.

#3

Last part of the Output:

 --------------------------------------------------------------
 
          Ground-State Mulliken Net Atomic Charges

     Atom                 Charge (a.u.)    Spin (a.u.)
  --------------------------------------------------------
      1 Fe                    0.108437      -0.000009
      2 Fe                   -0.075567      -0.000077
      3 S                    -0.644603       0.000001
      4 S                    -0.692293       0.000003
      5 S                    -0.584351       0.000001
      6 S                    -0.612626       0.000042
      7 S                    -0.574553       0.000035
      8 S                    -0.594552       0.000000
      9 H                    -0.083846      -0.000000
     10 H                    -0.062010       0.000005
     11 H                    -0.085062      -0.000002
     12 H                    -0.098975       0.000000
     13 Fe                    0.809823       4.054956
     14 N                    -0.424852       0.094529
     15 N                    -0.417466       0.100933
     16 N                    -0.417994       0.100988
     17 N                    -0.428254       0.096454
     18 C                     0.189867       0.000018
     19 C                     0.198247      -0.001520
     20 C                     0.187465      -0.000453
     21 C                     0.195923      -0.002425
     22 C                     0.196630      -0.002098
     23 C                     0.193579       0.000189
     24 C                     0.196414      -0.002825
     25 C                     0.192276      -0.000989
     26 C                     0.023324       0.007761
     27 C                     0.023210       0.004915
     28 C                     0.021613       0.008237
     29 C                     0.022841       0.005914
     30 C                     0.023030       0.004903
     31 C                     0.024054       0.007732
     32 C                     0.023264       0.005761
     33 C                     0.023627       0.009076
     34 H                    -0.038002       0.000641
     35 H                    -0.038427       0.000799
     36 H                    -0.038098       0.000634
     37 H                    -0.038771       0.000739
     38 H                    -0.038671       0.000778
     39 H                    -0.037793       0.000651
     40 H                    -0.038476       0.000762
     41 H                    -0.037764       0.000584
     42 C                    -0.048322       0.020725
     43 C                    -0.044160       0.020045
     44 C                    -0.043684       0.021033
     45 C                    -0.049201       0.020234
     46 H                    -0.043905      -0.001032
     47 H                    -0.043540      -0.000994
     48 H                    -0.043581      -0.001048
     49 H                    -0.044130      -0.000989
     50 S                    -0.281584       0.422394
     51 H                     0.091490       0.001989
  --------------------------------------------------------
  Sum of atomic charges =    -4.000000
  Sum of spin   charges =     5.000000

 -----------------------------------------------------------------
                    Cartesian Multipole Moments
 -----------------------------------------------------------------
    Charge (ESU x 10^10)
               -19.2128
    Dipole Moment (Debye)
         X    -743.0353      Y   -1056.2264      Z    -618.6252
       Tot    1431.9263
    Quadrupole Moments (Debye-Ang)
        XX  -29051.2633     XY  -40814.0251     YY  -58440.7294
        XZ  -23937.4539     YZ  -34003.5390     ZZ  -20268.2524
    Octopole Moments (Debye-Ang^2)
       XXX ************    XXY ************    XYY ************
       YYY ************    XXZ -937134.6193    XYZ ************
       YYZ ************    XZZ -784724.1681    YZZ ************
       ZZZ -677788.8576
    Hexadecapole Moments (Debye-Ang^3)
      XXXX ************   XXXY ************   XXYY ************
      XYYY ************   YYYY ************   XXXZ ************
      XXYZ ************   XYYZ ************   YYYZ ************
      XXZZ ************   XYZZ ************   YYZZ ************
      XZZZ ************   YZZZ ************   ZZZZ ************
 -----------------------------------------------------------------
 Total job time:  256.30s(wall), 712.82s(cpu) 
 Wed Dec 25 12:51:58 2024

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