Hi all,

I want to remove imaginary frequency in my dimer case, where one molecular is frozen. So, I used this input to run for frequency calculation but I am facing the issue:

$molecule

0 3

Dimer coordinates

$end

$rem

BASIS = cc-pVDZ

EXCHANGE = omegaB97XD

JOB_TYPE = frequency

SCF_CONVERGENCE = 10

MAX_SCF_CYCLES = 400

MAX_CIS_CYCLES = 400

UNRESTRICTED = true

SPIN_FLIP = 1

CIS_N_ROOTS = 4

THRESH = 14

CIS_STATE_DERIVATIVE = 1

FRZN_OPT = 1

FRZ_ATOMS = 36

point_group_symmetry = false

integral_symmetry = false

SOLVENT_METHOD = PCM

$end

$solvent

DIELECTRIC 32.613000

OPTICALDIELECTRIC 1.765709

$end

$frozen_opt

37:72

$end

output:

!!**!!**!!

!!Warning*!!

!!Desired analytical derivatives not available!!

!!Finite difference job might take a long time!!

!!

!!********************************************!!

2-order derivative to be evaluated numerically with 1-order analytical derivatives

Checking the input file for inconsistencies… …done.

Can anyone please tell me? where I am making a mistake?