Warning while doing SOC

Greetings,

I am trying to run a spin-orbit coupling calculation. However, I am getting the following warning which I am not sure I can ignore or not. Based on a similar topic on Q-Chem Talk, I got the impression that I shouldn’t be getting the warning and instead should be getting something similar to this:

SPIN-ORBIT COUPLING BETWEEN THE SINGLET GROUND STATE AND EXCITED TRIPLET STATE

=======================================================================================

The warning I get:

Q-Chem warning in module anlman/spin_orbit_couple.C, line 322:

** Spin-orbit coupling calculations are only implemented for**
** restricted CIS/TDDFT at this time.**

Below is my $rem and thank you for your help.

$rem
BASIS = GENERAL
ECP = GENERAL
ECP_FIT = TRUE
MEM_STATIC = 2000
MEM_TOTAL = 80000
MOLDEN_FORMAT =1
SYMMETRY = FALSE
SYM_IGNORE = TRUE
CIS_N_ROOTS = 10
CIS_CONVERGENCE = 8
CIS_SINGLETS = TRUE
CIS_TRIPLETS = TRUE
EXCHANGE = B3LYP
GUI = 2
NBO = 2
NTO_PAIRS = 2
UNRESTRICTED = 1
CALC_SOC = true
SET_ITER = 300
THRESH = 14
POP_MULLIKEN = 2
MAXSCF = 1700
MAX_CIS_CYCLES = 1000
SCF_CONVERGENCE = 5
SCF_ALGORITHM = DIIS_GDM
$end

The warning is triggered because you’ve requested an unrestricted calculation (UNRESTRICTED = 1). Ideally this error would be trapped during parsing of the input file, but apparently is not. The Q-Chem manual suggests that SOC support for unrestricted CIS/TDDFT was added in version 6.0: Release Log for Q-Chem 6.0 | Q-Chem

Hello @mofrad,

As @jherbert pointed out, the feature (unrestricted SOC) has been implemented in 6.0. You may request a free two-month demo to see if it works. Try on Your Own Computer | Q-Chem