Print symmetry labels for MOs

Questions
#1

Hi everyone,

How may I print the symmetry labels (for example, a1, b1, etc.) for the molecular orbitals in the output?

Thank you!

#2

Those labels should be printed out automatically if the symmetry is identify by the program. (sym_ignore = false)

#3

My output unfortunately does not contain these symmetry labels (this is a TD-DFT calculation)–is there a way I can get the program to print the irrep under the orbital?

Input:

$molecule
0 1
C 0 0 0
O 0 0 1.169152
O 0 0 -5.000
$end

$rem
JOBTYPE SP
METHOD B3LYP
CISTR_PRINT true
PBHT_ANALYSIS true
CIS_N_ROOTS 10
CIS_MAX_CYCLES 10000
RPA false
BASIS 6-31+G*
SCF_CONVERGENCE 13
MAX_SCF_CYCLES 20000
SCF_GUESS READ
PRINT_ORBITALS TRUE
IQMOL_FCHK TRUE
$end

Output:

--------------------------------------------------------------
 
                    Orbital Energies (a.u.)
 --------------------------------------------------------------
 
 Alpha MOs
 -- Occupied --
-19.3271 -19.2772 -10.3330  -1.1580  -0.9638  -0.5861  -0.4734  -0.4734
 -0.3923  -0.3801  -0.3801
 -- Virtual --
 -0.3000  -0.0569  -0.0569   0.0267   0.0428   0.0689   0.0689   0.1029
  0.1509   0.1509   0.1635   0.2124   0.2124   0.2191   0.2715   0.4107
  0.6299   0.6299   0.7177   1.0240   1.0716   1.0756   1.0756   1.1325
  1.1375   1.1375   1.2063   1.4739   1.4739   1.4763   1.5041   1.5041
  1.7083   1.7097   1.7097   1.7526   1.7526   1.9106   1.9106   2.4021
  2.5618   2.5618   2.9734   3.6011   3.9797   4.1467
 --------------------------------------------------------------
#4

I was able to reproduce this behavior. Looks like for infinite groups there is an issue that prevents orbital symmetries from being evaluated and printed out. We will take a further look and post an update.

#5

For molecules with a linear geometry, no symmetry labels are printed.
I usually assign the state by the orbital excitation amplitudes.

#6

Looking at the code it appears that the determination of orbital irreps for infinite groups is not implemented. A possible way around is to work within an Abelian subgroup and map the irreps back to the original group by visually inspecting the MOs. To reduce the symmetry to the largest Abelian subgroup, set USE_ABELIAN_SUBGROUP=TRUE in the input $rem.