Go to gaussian calculate set up- select job type  energy- select method- instead of ground state select TD-SCF and do other set up as usual. the submit fro running the programe.

In the output file opened with Gauss view select result-select uv - you will have spectrum

All the best

Fr.Xavier

You can use this to run your calculations. Of course you can change the functional/base and number of td. Be careful, these theoretical spectra changes drastically with both functional/base. CAM-B3LYP worked nicely for me.

#P CAM-B3LYP/6-311++G** td=(nstates=100) SCF=VeryTight IOp(9/40=2)

Name

-Charge Multi.

X Y Z

Good luck!

Hello,

Let me give a theoretical answer without going too much into technicalities. Firstly,   for your calculation you need excited states. These many-body excited states will ensure that you have correlations included in your calculations. You can calculate the many body excited states by various programs namely CASSCF, SAC-CI, EOM-CCSD (G09 although). In our opinion the CAS-SCF is the best possible method as it handles the static as well as dynamic correlations correctly. However the number of excited states you can calculate with this method is restricted to 25 I think. SAC-CI on the other hand is very powerful method and it handles the dynamic correlations very correctly. You can calculate many excited states with it and then can determine the symmetry of the states. This stage is very crucial as you have to determine the oscillator strengths. I;m not sure if there are any programs available which you can use as a black box to calculate the spectra apart from the IR spectra. Once you calculate the oscillator strength the rest is very straight forward to determine. 

hello

simply first, you have to optimize the geometry (ground state) and then considering this optd geometry, you do single point calcns using the TD option; You can also check the g03 output; here also it gives the oscillator strength, and absorption values without uisng the gaussview. Refer the gaussian manual

bye 

the methods that r suggested by xavier and j.l.rao will prove helpful for you . as you said that u r new to g03 try using their suggestions. your job will be done and u will get ur uv -vis spectra 

after optimized the structure (in solvent)

you need to add the key word  pop=full iop(3/33=1,3/36=-1) to the energy input file

then from the output of the previous step do a td calculation

td=(nstates=20) IOP(9/40=2) 

Dear All,

I am a beginner with G09. My project is concerned with UV-Vis absorbance and fluorescence. Could you please advise where i can find templates for route sections for determination of 1) Absorption spectrum 2) Fluorescence spectrum 3) kind of transition e.g. S0---S1 4) Charge transfer 5) n-pi* or pi-pi* transitions 6) Stoke's shift and transition energy 7) ......... To sum up, i need a comprehensive guide for all UV-Vis jobs that can be done on G09 under linux environment (supercomputer).

Dear Sir,

I am having output file of my compound. but i dont have Gaussian software. is it possible to calculate UV-Vis absorption spectra, fluorescence spectra and optimized geometry of the compound.

i prefer u to consult mr. raos answer 

you do TD-SCF

in the calculation bar click on the method click on td scf option and click on the no of excited states =6 ur output file will give u the absorption spectra

Hi, the Uv-Visible calculation for a molecule was performed using Gaussian 09. I have observed LAMBDA max with ZERO oscillator strength. What does it mean? When  the transition is not possible at  LAMBDA max (since f=0). Why does it need to be LAMBDA max?

do the following steps to calculate the UV_spectrum

1. Optimize the molecule with suitable method and basis set ( check the literature for this) depending on your molecule

2. Then take the optimized geometry from the above step and do TD-DFT calculation

(option: you can include the solvent also) using TD(SINGLETS, NSTATES=10)

3.  Compare the calculated  absorption spectra (lamda max) with the experiment, taking f >0.0. ( you can view the spectra using gaussview software.

4. Change the method/basis set, if the spectra is not in good agreement with expt

Hope this can help you

How off should be the emission max calculated from gaussian be? I am getting an emission max of 368 nm while the experimental is 400 nm for a compound.

What can I do to improve my results? I am using b3lyp/ 6-311+G**?

Joshi Laxmikanth Rao Hello sir, how to calculculate UV vis Spectrum for Absorbtion by using Gaussian Linux version.? I need a İnput file example that is about any material. İ use Gaussian Linux version. Also I know that in Windows operating system has Gaussian version. But the material is so complex so window version can not be calculate fast.