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["Davide Sangalli" <davide.sangalli@gmail.com>]

Dear forum,
    I'm studying the N2+ molecule within DFT/TDDFT.
I founded out that, increasing the super-cell dimension
(i.e. increasing acell) the total energy of the system is
increasing (decreasing in module) while the values of
the KS eigenvalue are decreasing (increasing in module
the negatives ones)

Am I getting this because N2+ is a charged molecule?
My input file follows here.

Thanks,
Davide
_________________________________________________

# N2+ TDDFT calculation
# Ground state working within DFT

 ndtset   2
#mkmem    1 

# Type of molecules to be studied
 natom     2
 ntypat    1
 typat     1 1
 znucl     7 7
 nsppol    2
 occopt    2
 occ1      1  1  1  1  0  0  0  0  0  0
              1  1  1  1  1  0  0  0  0  0
 occ2      1  1  1  1  0  0  0  0  0  0  20*0
              1  1  1  1  1  0  0  0  0  0  20*0
 charge    +1

# Primitive cell choosed and position of atoms inside it 
 acell      3*16 Angstrom
 xangst     7.4418   8   8    # d=1.1164 (1.0977) Angstrom
                8.5582   8   8

# Parameters for the SCF calculation            
 ecut      20
 nstep     25
#nbdbuf    0
 
# It's an isolated system so nkpt=1, other thinghs I took from
# the tutorial 
 nkpt      1
 diemac    1.5
 diemix    0.5

# First step.

# Calculation of ground state.
 ixc1      1
 iscf1     5
 tolwfr1   1.0d-11
 nband1    10  10 
 prtden1   1
 getwfk1   0

# Second step
# TDDFT excitation
 ixc2      1
 iscf2    -1
 tolwfr2   
1.0d-11 
 nband2    30 30
 getden2   1
 getwfk2   1