exciton wfs with fixed electron position

[michele guerrini]

Dear developers,
is it possible by using ypp to plot the hole probability distribution with fixed electron position ?

[Daniele Varsano]

Hi Michele,

no, but it should be straightforward to modify the code for that:
/ypp/excitons/excitons_WFs.F

Just assign the r_hole position as an electron position by swithcing the ir_hole position nad ir in WF1_ir (valence) to WF2_ir (conduction).
:
WF1_ir=WF_symm(rindex(ir_hole),(/iv,ikibz,is,i_spin/))
WF2_ir=WF_symm(rindex(ir ),(/ic,ikibz,is,i_spin/))

Best,
Daniele

[michele guerrini]

thank you very much Daniele, it seems working fine !

[pangrt]

Dear all,
When we construct exciton wavefunctions, we always chose a fixed hole position and see what are the electron distributions, and we call the fixed hole and electron distributions together the exciton wavefunctions. Could we fix an electron of the exciton, and see how the distribution of the holes? What the difference between the fixed h and fixed e for the exciton wavefunction?

Thanks!

Pang rt


IMU,Hohhot, China

[Daniele Varsano]

Dear Pang,

if you look at the definition of the excitonic wfs you realise that the hole coordinate refers to the valence bands/orbitals and electrons to the conductions one participating in the excitation. If you want to fix the electron coordinates instead of the hole probably it is enough to change in the code:
/ypp/excitons/excitons_WFs.F

Code: Select all

190        WF1_ir=WF_symm(rindex(ir_hole),(/iv,ikp,isp,i_spin/))
191        WF2_ir=WF_symm(rindex(ir     ),(/ic,ikibz,is,i_spin/))

in

Code: Select all

190        WF1_ir=WF_symm(rindex(ir),(/iv,ikp,isp,i_spin/))
191        WF2_ir=WF_symm(rindex(ir_hole     ),(/ic,ikibz,is,i_spin/))

and recompile it.

Best,
Daniele

[sdwang]

Dear all,
I want to obtain the hoe distributions while fixing the electron position, I change the code /ypp/excitons/excitons_WFs.F from
242 WF1_ir=WF_symm(rindex(ir_hole),(/iv,ikp,isp,i_sp_pol/))
243 WF2_ir=WF_symm(rindex(ir ),(/ic,ikibz,is,i_sp_pol/))
to
242 WF1_ir=WF_symm(rindex(ir ),(/iv,ikp,isp,i_sp_pol/))
243 WF2_ir=WF_symm(rindex(ir_hole),(/ic,ikibz,is,i_sp_pol/))
I find the code of excitons_WFs.F is really different from the previous version. Is it enough to capture the hole distribution?

Thanks

Best,

Shudong

[Daniele Varsano]

Dear Shudong,

yes this should be enough.

Best,
Daniele

[Davide Sangalli]

If you want to fix the electron coordinates instead of the hole probably it is enough to change in the code:
/ypp/excitons/excitons_WFs.F

Code: Select all

190        WF1_ir=WF_symm(rindex(ir_hole),(/iv,ikp,isp,i_spin/))
191        WF2_ir=WF_symm(rindex(ir     ),(/ic,ikibz,is,i_spin/))

in

Code: Select all

190        WF1_ir=WF_symm(rindex(ir),(/iv,ikp,isp,i_spin/))
191        WF2_ir=WF_symm(rindex(ir_hole     ),(/ic,ikibz,is,i_spin/))

I'd say that you also need to fix the phase factor defined just before

Code: Select all

         k_dot_r_e  = dot_product(r_cell_cc(:,ir),Xk%ptbz(ikbz,:)/alat(:))*2._SP*pi
         kp_dot_r_h = dot_product(r_hole,Xk%ptbz(ikpbz,:)/alat(:))*2._SP*pi

should be replaced by

Code: Select all

         k_dot_r_e  = dot_product(r_hole,Xk%ptbz(ikbz,:)/alat(:))*2._SP*pi
         kp_dot_r_h = dot_product(r_cell_cc(:,ir),Xk%ptbz(ikpbz,:)/alat(:))*2._SP*pi

and recompile it.

Best,
Daniele