[molpro-user] nature of excited states in EOM-CC

[Tatiana Korona]

Dear Anastassia,

I list below the example input file showing different possibilities of 
exploring EOM-CCSD eigenvectors, which I put into my program:

***, Properties and transition moments for several lowest states of hydrogen fluoride
memory,2,m
basis=avdz                                       ! define basis set
geometry={h;f,h,r}                               ! z-matrix
r=0.92 Ang                                       ! define distance

hf                                               ! do SCF calculation
{ccsd                                            ! do CCSD calculation
dm,5600.2                                        ! density matrices will be stored here
expec,qm                                         ! require quadrupole moments
eom,-3.1,-2.2,-2.3,-2.4,trans=1}                 ! do EOM-CCSD calculation + properties

! WAY 1
pop;density,5600.2,state=2.4                     ! population analysis for state 2.4

! WAY 2
{ccsd
eom,-3.1,-2.2,-2.3,-2.4
eomprint,popul=1                                 ! make Loewdin population analysis of 
}                                                ! the singles part of RHS EOM-CCSD eigenvector

! WAY 2'
{ccsd
eom,-3.1,-2.2,-2.3,-2.4,mullprint=1
eomprint,popul=1                                 ! make Mulliken population analysis of 
}                                                ! the singles part of RHS EOM-CCSD eigenvector


! WAY 3
set zsymel=nosym
geometry={h;f,h,r}                               ! z-matrix
hf
!locali,pipek                                    ! if uncommented, produce localized occupied orbitals,
                                                  ! but this will be still the nonlocal EOM-CCSD calculation.
                                                  ! Localizing occupied orbitals can be useful for visualization
                                                  ! of electronic excitations (from which part of molecule to
                                                  ! which the excition goes)
put,molden,hf.molden
{ccsd
eom,2.1,emolden=1                                ! produce a molden-like file for "natural virtual orbitals"
}                                                ! defined as \phi*_i=sum_a r^i_a \phi_a, r^i_a are EOM-CCSD
! coefficients for the RHS eigenvector, \phi_a are virtual
! orbitals, so \phi*_i is the whole excitation from the occupied
! orbital \phi_i. Works for symmetry=1 only.
! Example pictures: see in TK,HJW, J.Chem.Phys.,118,3006 (2003)
! Note that this file (called xxx.emolden2 for the input xxx.inp) is
! not complete and one should take the preamble (everything from the beginning
! up to [GTO] line) from the file hf.molden.
! Orbital energies in xxx.emolden2 file are just the orbital energies of
! original occupied orbital.


Best wishes,

Tatiana

On Thu, 12 Nov 2009, Anastassia Alexandrova wrote:

> Hi All,
> Is there a way to know the electronic configuration of excited states, whose
> energies are calculated with EOM-CCSD? That is, I need to know the structure
> of MOs, or their composition in terms of basis functions, fort he excited
> states. My system has no symmetry, so there is no way I could guess the
> order of the states EOM produces. Thank you!
> Anastassia
>

Dr. Tatiana Korona http://tiger.chem.uw.edu.pl/staff/tania/index.html
Quantum Chemistry Laboratory
University of Warsaw
Pasteura 1, PL-02-093 Warsaw, POLAND


`The man who makes no mistakes does not usually make anything.'
                                        Edward John Phelps (1822-1900)