[Pw_forum] Eigenfunctions in PWSCF

[Min Seung Kyu]

Dear users and developers,

I have a question about eigenfunctions in PWSCF codes.

I looked at PWSCF source files and I found that the 'evc' variable is 
KS eigenvectors in G-space, right?

Because Hamiltonian matrix H(G,G') is hermitian, 'evc' should be real.

When I print out 'evc', however, 'evc' contains imaginary parts.

For example, when I run 'co.rx.in' (example03 folder), I got these values:

  DBLE(evc(1:4,1))     0.186884     0.154551     0.154551     0.142085
AIMAG(evc(1:4,1))     0.000000     0.000000     0.000000    -0.048560
  DBLE(evc(1:4,2))    -0.024799    -0.021751    -0.021751    -0.068645
AIMAG(evc(1:4,2))     0.000000     0.000000     0.000000    -0.145963
  DBLE(evc(1:4,3))     0.000000     0.000000     0.000000     0.000000
AIMAG(evc(1:4,3))     0.000000    -0.005668     0.152298     0.000000
  DBLE(evc(1:4,4))     0.000000     0.000000     0.000000     0.000000
AIMAG(evc(1:4,4))     0.000000    -0.152298    -0.005668     0.000000
  DBLE(evc(1:4,5))    -0.299154    -0.185970    -0.185970     0.011252
AIMAG(evc(1:4,5))     0.000000     0.000000     0.000000     0.168998

( I added 'WRITE(*,*) evc(1:4,ibnd)' in 'sum_band.f90'. )

What is the problem?

Thank you in advance.

Sincerely, Min.

-------------------------------Sig.---------------------------
Center for Superfunctional Materials, Department of Chemistry,
Pohang University of Science and Technology (POSTECH)

Mr. Seung Kyu, Min

Ph.D. Candidate

E-Mail: min0220 at postech.ac.kr
Tel.  : 82-54-279-5858
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