Multiwfn forum

Multiwfn official website: http://sobereva.com/multiwfn. Multiwfn forum in Chinese: http://bbs.keinsci.com/wfn. E-mail of admin: sobereva[at]sina.com

You are not logged in.

#1 2018-10-26 05:06:11

sobereva
Tian Lu (Multiwfn developer)
From: Beijing
Registered: 2017-09-11
Posts: 134
Website

Wavefunction analysis of TDDFT excited states for ORCA users

Today an ORCA user asked a question about how to calculate Lowdin and/or Mulliken charges as well as Mayer bond order of ground and excited state of a molecule (https://orcaforum.cec.mpg.de/viewtopic. … 82&p=17541), below is my reply, I copy it here because my reply may be useful for other Multiwfn users:

I am not sure if ORCA itself has this capacity (seemingly impossible for present version if I remembered correctly), but this can be easily realized by using Multiwfn program (http://sobereva.com/multiwfn) based on ORCA output file.

After loading .molden file generated by ORCA into Multiwfn, you will be able to study ground state electronic structure, various kinds of atomic charges and bond orders can be evaluated by main functions 7 and 9, and there are lots of examples in Section 4.7 and 4.9 of the Multiwfn maunal, respectively.

If you want to use Multiwfn to study excited state wavefunction, you should first generate .molden file containing nature orbitals of the excited state of your interest. You should first use ORCA to carry out a normal electron excitation calculation via keywords like below (see beginning of Section 3.21 of Multiwfn manual for detail):
! PBE0 def2-SVP nopop
%tddft
nroots 8
tprint 1E-8
end

Assume that the output file is exc.out and the generated .molden file via orca_2mkl is exc.molden.input, then after boot up Multiwfn you should input:
exc.molden
18 // Electron excitation analysis
13 // Generate natural orbitals of specific excited states
exc.out
4 // Assume that the 4th excited state is the one you want to study
Now you will find NO_0004.molden has been generated in current folder. Using this file as input file of Multiwfn, the calculated quantities such as atomic charges and bond orders will correspond to the 4th excited state.

Note that above mentioned way is strict for CIS or the TDDFT under TDA approximation. For TDHF and regular TDDFT, the result obtained in above way may or may not be very reliable (because current version of ORCA does not print excitation and de-excitation coefficients separately).

Offline

Board footer

Powered by FluxBB