This is a part of the output file for fluorescence emission calculation.

Input : #p opt td=(singlets,root=1) b3lyp/genecp scrf=(solvent=methanol) geom=
connectivity

I have calculated emission spectra. When do orbital contribution calculation I have to consider transition from 145 ---->147 ?
or I understood this wrongly?

Excitation energies and oscillator strengths:

Excited State   1:      Singlet-A      1.2577 eV  985.84 nm  f=0.0047  <S**2>=0.000
     145 ->147         0.68259
This state for optimization and/or second-order correction.
Total Energy, E(TD-HF/TD-KS) =  -3027.47515828
Copying the excited state density for this state as the 1-particle RhoCI density.

Excited State   2:      Singlet-A      1.7817 eV  695.89 nm  f=0.0001  <S**2>=0.000
     144 ->147        -0.67710

Excited State   3:      Singlet-A      1.9683 eV  629.89 nm  f=0.0027  <S**2>=0.000
     145 ->146         0.69194
SavETr:  write IOETrn=   770 NScale= 10 NData=  16 NLR=1 NState=    3 LETran=      64.
The selected state is a singlet

Gaussian is able to calculate emission energy of phosphorescence spectrum, but it is unable to yield oscillator strength of this kind of spectrum (in other words, the printed oscillator strength is always exactly zero), since non-vanishing oscillator strength of T1->S0 emission comes from spin-orbit coupling effect, which cannot be considered by Gaussian at TDDFT level. Usually Dalton program is suggested to compute oscillator strength between T1 and S0.

I cannot understand your second question.

I have successfully plot fluorescence spectra by following the instructions stated by you (http://sobereva.com/wfnbbs/viewtopic.php?id=413).

1. My question is can we plot phosphorescence spectra using exactly same steps?

11 // Plotting spectra
3 // UV-Vis
20 // Modify oscillator strengths
2-3 // Choose S2 and S3 states
0 // Set oscillator strengths to zero (because emission is from S1 state)
0 // Plot spectrum

Becouse phosphorescence is T1---->S0 transition.

Another thing is when people mean emission spectra which one in transition metal complexes.
fluorescence, phosphorescence, or both?

Thank you

Use following keywords for optimizing T1
#p td(triplet) b3lyp/genecp scrf=(solvent=methanol) geom=connectivity opt

Note that S1 and T1 must be optimized separately, 50-50 cannot be used in this context. guess=save is meaningless. It is unnecessary to set nstates as large as 10, because this will notably increase computational cost while the S1 / T1 will not be detectably affected.

I need to plot emission spectra of Ru transition metal complexes.
This is my input for optimization.
Is this correct?
I need both fluorescence and phosphorescence.
Can I take the output of this calculation to obtain the emission spectra using Multiwfn

%mem=4GB
%nprocshared=4
%chk=Neutral.chk
#p td=(50-50,nstates=10,root=1) b3lyp/genecp scrf=(solvent=methanol)
guess=save geom=connectivity opt

Neutral Fluoride Complex from the X-ray crystal structure

0 1
Ru                 0.49152900   -1.00287600    0.09326700
Cl                 0.66506000   -1.18796400   -2.33847900
Cl                 0.96242300   -1.06595000    2.50569800
P                 -1.14911300    0.54149000    0.02331800
F                  2.76034900   -1.90860800    0.00631700
N                  1.77532400    0.64178100   -0.02843200
O                 -2.22603700   -2.70087200    0.96397000
S                 -0.87762300   -2.87042900    0.29049200
C                  1.27960300    1.90403300   -0.05083200
C                 -0.13813900    2.08851300   -0.01943800
C                 -0.64790200    3.36905700    0.00649500
H                 -1.72172700    3.52421800    0.05440300
C                  0.20504300    4.50762600   -0.02719900
H                 -0.23475300    5.49948700   -0.01111100
C                  1.56632600    4.35252600   -0.08013500
H                  2.22538600    5.21520600   -0.10762500
C                  2.14873400    3.04896800   -0.08989900
C                  3.53085900    2.83652700   -0.12465600
H                  4.20665800    3.68669100   -0.15556800
C                  4.05139700    1.53821100   -0.11568800
C                  5.45120700    1.25536100   -0.15050600
H                  6.14675600    2.08773100   -0.19077900
C                  5.90357800   -0.03875900   -0.13249900
H                  6.96691600   -0.25133600   -0.15894000
C                  4.98721500   -1.12783200   -0.07836500
H                  5.33654100   -2.15449100   -0.06390000
C                  3.65038400   -0.86564600   -0.04418000
C                  3.11234700    0.44907000   -0.06204300
C                 -1.19758300   -3.75212800   -1.26942600
H                 -1.79914200   -4.63222900   -1.02933400
H                 -0.25052300   -4.02752200   -1.73610500
H                 -1.74514100   -3.07082800   -1.92117300
C                 -0.00292000   -4.20020300    1.17802700
H                  0.23376000   -3.81407100    2.17029700
H                  0.91641400   -4.44979400    0.64186000
H                 -0.66776000   -5.06540600    1.23910000
C                 -2.18596100    0.55229000   -1.50150700
C                 -3.18113500   -0.43327200   -1.62938500
H                 -3.34446200   -1.14905100   -0.82796800
C                 -3.96636500   -0.49594700   -2.78073900
H                 -4.73480500   -1.25924300   -2.86603300
C                 -3.76744600    0.42012100   -3.81820500
H                 -4.38023800    0.37087500   -4.71387100
C                 -2.78018900    1.39921300   -3.69735000
H                 -2.62036000    2.11581000   -4.49811900
C                 -1.99099500    1.46594500   -2.54554700
H                 -1.22701800    2.23231700   -2.46900500
C                 -2.38962000    0.87519600    1.35444700
C                 -3.60606500    1.51256500    1.05151600
H                 -3.85995700    1.75348300    0.02521400
C                 -4.50566300    1.84038400    2.06810900
H                 -5.44108100    2.33239300    1.81668500
C                 -4.20643400    1.53429500    3.39706000
H                 -4.90946000    1.78576800    4.18632200
C                 -3.00006700    0.90154900    3.70558200
H                 -2.76052400    0.65709200    4.73687400
C                 -2.09536100    0.57430500    2.69378500
H                 -1.16252800    0.08069500    2.94054800

1 4 1.0 8 1.0
2
3
4 10 1.0 37 1.0 48 1.0
5 27 1.0
6 9 1.5 28 1.5
7 8 1.5
8 29 1.0 33 1.0
9 10 1.5 17 1.5
10 11 2.0
11 12 1.0 13 1.5
12
13 14 1.0 15 2.0
14
15 16 1.0 17 1.5
16
17 18 1.5
18 19 1.0 20 1.5
19
20 21 1.5 28 1.5
21 22 1.0 23 2.0
22
23 24 1.0 25 1.5
24
25 26 1.0 27 2.0
26
27 28 1.5
28
29 30 1.0 31 1.0 32 1.0
30
31
32
33 34 1.0 35 1.0 36 1.0
34
35
36
37 38 1.5 46 1.5
38 39 1.0 40 1.5
39
40 41 1.0 42 1.5
41
42 43 1.0 44 1.5
43
44 45 1.0 46 1.5
45
46 47 1.0
47
48 49 1.5 57 1.5
49 50 1.0 51 1.5
50
51 52 1.0 53 1.5
52
53 54 1.0 55 1.5
54
55 56 1.0 57 1.5
56
57 58 1.0
58

C H P N F S O 0
6-31G(d)
****
Cl
6-31+G(d)
****
Ru 0
SDD
****

Ru 0
SDD

Thanks and regards,
Gayani