How do you troubleshoot "inconsistent or unspecified charge/multiplicity"?

[Kuzhanthaivelan]

Hi all,
I am trying to run SAPT calculations through PSI4. I ran a basic examples of dimer molecules and it ran successfully. Then I tried to run a SAPT calculation for Protein-Ligand complex. As I am a beginner, I took only one residue from protein (methionine) and ligand to run the calculation. The calculation returned with error immediately with inconsistent or unspecified charge/multiplicity. I have pasted the error message below,

c: [0]
fc: [0.0]
fc: [0.0]
m: [1]
fm: [1]
fm: [1]
Traceback (most recent call last):
File “/home/rsistla/anaconda3/envs/psi4_1.9/bin/psi4”, line 387, in
exec(content)
File “”, line 18, in
File “/home/rsistla/anaconda3/envs/psi4_1.9/lib/python3.10/site-packages/psi4/driver/molutil.py”, line 265, in geometry
molrec = qcel.molparse.from_string(
File “/home/rsistla/anaconda3/envs/psi4_1.9/lib/python3.10/site-packages/qcelemental/molparse/from_string.py”, line 276, in from_string
molrec = from_input_arrays(
File “/home/rsistla/anaconda3/envs/psi4_1.9/lib/python3.10/site-packages/qcelemental/molparse/from_arrays.py”, line 97, in from_input_arrays
processed = from_arrays(
File “/home/rsistla/anaconda3/envs/psi4_1.9/lib/python3.10/site-packages/qcelemental/molparse/from_arrays.py”, line 380, in from_arrays
processed = validate_and_fill_chgmult(
File “/home/rsistla/anaconda3/envs/psi4_1.9/lib/python3.10/site-packages/qcelemental/molparse/chgmult.py”, line 501, in validate_and_fill_chgmult
c_final, fc_final, m_final, fm_final = reconcile(cgmp_exact_c, cgmp_exact_fc, cgmp_exact_m, cgmp_exact_fm)
File “/home/rsistla/anaconda3/envs/psi4_1.9/lib/python3.10/site-packages/qcelemental/molparse/chgmult.py”, line 491, in reconcile
raise ValidationError(err)

qcelemental.exceptions.ValidationError: Inconsistent or unspecified chg/mult: sys chg: None, frag chg: [0.0, 0.0], sys mult: None, frag mult: [1, 1]

Printing out the relevant lines from the Psithon → Python processed input file:
geometry(“”"
0 1
H 0 0 0
H 0.74 0 0
“”“,“blank_molecule_psi4_yo”)
→ pdb6LXY_ligand = geometry(”“”
0 1
N 19.613001 -12.863000 4.678000
C 20.497000 -12.789000 5.857000
C 19.702999 -13.034000 7.157000
O 19.007000 -12.140000 7.650000

!----------------------------------------------------------------------------------!
! !
! Inconsistent or unspecified chg/mult: sys chg: None, frag chg: [0.0, 0.0], sys !
! mult: None, frag mult: [1, 1] !
! !
!----------------------------------------------------------------------------------!

Can someone help me what mistake I did here? Any help/suggestions would be highly appreciated.

Thank you.

[Kuzhanthaivelan]

Here is my input for the above post.

molecule pdbLXY_ligand {
0 1
N 19.613001 -12.863000 4.678000
C 20.497000 -12.789000 5.857000
C 19.702999 -13.034000 7.157000
O 19.007000 -12.140000 7.650000
C 21.273001 -11.440000 5.892000
C 22.219999 -11.241000 4.703000
S 23.750000 -12.205000 4.866000
C 23.457001 -13.485000 3.708000
H 19.567646 -13.635435 4.028857
H 19.756647 -14.006675 7.646005
H 19.066000 -12.028000 4.623000
H 21.236000 -13.578000 5.720000
H 20.566000 -10.610000 5.908000
H 21.858999 -11.377000 6.809000
H 21.722000 -11.531000 3.778000
H 22.481001 -10.187000 4.607000
H 22.999001 -14.335000 4.214000
H 22.788000 -13.123000 2.928000
H 24.402000 -13.794000 3.261000
–
0 1
N 21.530001 -6.336000 0.516000
C 21.475000 -8.642000 1.168000
O 14.216000 -10.185000 11.475000
C 22.141001 -7.626000 0.485000
N 21.936001 -5.198000 -0.120000
O 15.819000 -8.311000 7.808000
C 20.989000 -4.278000 0.205000
N 19.681000 -7.138000 1.931000
C 19.988001 -4.792000 1.035000
N 19.621000 -9.344000 2.693000
C 20.320999 -6.121000 1.231000
N 18.381001 -10.425000 4.398000
C 20.250000 -8.360000 1.905000
N 16.419001 -10.508000 7.957000
C 18.930000 -9.236000 3.919000
N 17.540001 -6.747000 6.375000
C 17.611000 -10.367000 5.503000
C 17.341999 -9.179000 6.196000
C 16.451000 -9.265000 7.366000
C 15.554000 -10.816000 9.079000
C 16.268000 -10.778000 10.450000
C 15.268000 -11.129000 11.627000
C 15.972000 -10.968000 12.992000
C 14.752000 -12.591000 11.549000
C 17.899000 -7.924000 5.720000
C 17.948000 -5.361000 6.060000
C 17.796000 -4.490000 7.316000
C 17.002001 -4.840000 4.973000
C 18.740999 -7.970000 4.554000
F 21.931000 -9.867000 1.092000
F 16.719000 -9.515000 10.609000
H 13.491000 -10.384000 12.135000
H 19.127001 -4.260000 1.440000
H 15.145000 -11.816000 8.933000
H 14.741000 -10.090000 9.095000
H 17.073999 -11.511000 10.476000
H 23.076000 -7.807000 -0.045000
H 16.492001 -11.892000 13.244000
H 15.230000 -10.748000 13.760000
H 16.691000 -10.150000 12.936000
H 15.596000 -13.267000 11.411000
H 14.066000 -12.690000 10.708000
H 14.232000 -12.843000 12.473000
H 18.983999 -5.330000 5.723000
H 18.412001 -4.898000 8.118000
H 16.752001 -4.482000 7.628000
H 18.117001 -3.472000 7.093000
H 17.141001 -5.422000 4.062000
H 17.222000 -3.792000 4.772000
H 15.971000 -4.936000 5.312000
H 19.218000 -7.070000 4.167000
H 21.007000 -3.247000 -0.146000
H 19.672001 -10.273000 2.322000
H 18.552000 -11.296000 3.935000
H 17.014000 -11.227000 7.598000
H 16.927000 -6.855000 7.158000
H 17.174000 -11.294000 5.876000

 units angstrom
 no_reorient
 symmetry c1

}

set basis aug-cc-pvdz

energy(‘sapt0’)

[jmisiewicz]

You got an error saying that the charge and multiplicity are inconsistent because the charge and multiplicity are inconsistent.

In a case like this, the first thing to do is to check if Psi runs a HF for any of the individual monomers. Trying that would you show you that the problem is in monomer two.

More specifically, you told Psi that your second molecule is in a singlet spin state and is electrically neutral. It isn’t. For organic ligands, this normally means your atoms are incorrect or that this ligand is ionic.