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[Dev Sharma <champbond1983@gmail.com>]

hi 2 all,

Actually , i want to see that in YVO4, which excitations/transitions are possible or not ??? is it time dependent Density functional theory is correct tool for that ??

I studied the Tutorial TDDFT and modify my input file according to that , but i have some doubts.

1) YVO4 space group is I41/amd but my output is giving 
DATASET    1 : space group P2 (#  3); Bravais mP (primitive monocl.)
where i am much sure about my atomic positions . Please help

2) Secondly nband is 
Gives number of bands, occupied plus
possibly unoccupied, for which wavefunctions are being computed
along with eigenvalues.
like now i have specified 100, how will i got to know that how may are occupied and how many unoccupied ???

3) Similar;y, In ttddft example, there are 5 occupied and 7 unoccupied bands, with total, 12. But in dataset 1 nband1 is 5 that means 5 is total occupied+unoccupied. I am somewhat confused here. 

4) Finally in the tutorial/lesson_ttddft.html it is written there

To summarize our results, we obtain the following five lowest-lying spin-singlet excitation energies, with corresponding quantum numbers (that we derive from the knowledge of the Kohn-Sham states quantum numbers):

9.47 eV   m=+1,-1  even parity (Pi_g state)
9.86 eV   m=0      even parity (Sigma_g state)
9.91 eV   m=0      odd parity  (Sigma_u state)
10.46 eV  m=+2,-2  odd parity  (Delta_u state)
10.79 eV  m=+1,-1  odd parity  (Pi_u state)

Can somebody tell me, how they have find here m . parity and Pi_g states ???

Please help
Dev
 My Input file is listed below
========================


 ndtset    2

#DATASET 1  SCF
   iscf1   5
 tolwfr1   1.0d-15
  nband1   100
 prtden1   1
 getwfk1   0

#DATASET 2 TDDFT
   iscf2  -1
 tolwfr2   1.0d-9
  nband2   150
 getden2   1
 getwfk2   1

#Common
 acell 13.451637476  13.451637476  11.885054518   
  angdeg  90 90 90 
 boxcenter 3*0.0d0
 diemac 12   diemix 0.5d0
 ecut 10
 ixc  7

kptopt 0          # Enter the k points manually 

 natom  24 
 nbdbuf 0

 nstep 25
 ntypat  3
 typat 1 1 1 1 2 2 2 2  3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3  
 xangst               
             0.000000000   5.338725356    0.786162553
             3.559150238   1.779575118    3.930812762
             3.559150238   5.338725356    2.358487657
             0.000000000   1.779575118    5.503137866
             0.000000000   1.779575118    2.358487657
             3.559150238   5.338725356    5.503137866
             0.000000000   5.338725356    3.930812762
             3.559150238   1.779575118    0.786162553
             0.000000000   3.090765987    1.262891534
             3.559150238   6.649916224    4.407541744
             3.559150238   4.027534488    4.407541744
             0.000000000   0.468384251    1.262891534
             5.807109607   5.338725356    2.835216639
             4.870341106   1.779575118    5.979866849
             3.559150238   3.090765987    1.881758675
             0.000000000   6.649916224    5.026408885
             0.000000000   4.027534488    5.026408885
             3.559150238   0.468384251    1.881758675
             4.870341106   5.338725356    0.30943357
             5.807109607   1.779575118    3.45408378
             1.311190868   1.779575118    3.45408378
             2.247959369   5.338725356    0.30943357
             2.247959369   1.779575118    5.979866849
             1.311190868   5.338725356    2.835216639

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