The ABINIT Users Mailing List ( CLOSED )

[Dev Sharma <champbond1983@gmail.com>]

Dear Sir,

If i use the EXC code, for its configuration with abinit , i have to specify any path or i can just install with the commands
./configure
make
make test
make install

and then after GW step
i can use directly
exc -k file.kss -e file.scr -g file.gw -i input > exc.log & 

will it work or i have to make any interface with abinit ???
Thnaks
Dev Sharma,
University of Delhi,
India

On Sat, Oct 17, 2009 at 6:09 PM, Xavier Gonze <xavier.gonze@uclouvain.be> wrote:

Dear Dev Sharma,

The TDDFT implemented in ABINIT is Casida method (for TDLDA), which departs from the
difference of Kohn-Sham eigenenergies only with finite systems. Thus is it useless
to try YVO4. If you want a quasi-particle band structure, you have to do a GW calculation.
And if you want the neutral excitations (e.g. excitons), you have to do a GW-ABINIT run followed by an EXC
or YAMBO run. See http://www.etsf.eu .

For GW, read the corresponding tutorial from the ABINIT Web site...

Best,
Xavier

On 17 Oct 2009, at 14:24, Dev Sharma wrote:

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

 znucl  39 23 8