### output file of BSE

Posted:

**Sat May 22, 2010 1:02 pm**Dear all"

I have calculate my 2D rectangle unitcell including 4C atoms and 2O atoms with pwscf v4.1.2, then I do a BSE calculation.I type >yambo -o b -b -y h,and edit input file as:

optics # [R OPT] Optics

bse # [R BSK] Bethe Salpeter Equation.

em1s # [R Xs] Static Inverse Dielectric Matrix

bss # [R BSS] Bethe Salpeter Equation solver

BSresKmod= "xc" # [BSK] Resonant Kernel mode. (`x`;`c`;`d`)

% BSEBands

1 | 18 | # [BSK] Bands range

%

BSENGBlk= 1 RL # [BSK] Screened interaction block size

BSENGexx= 2027 RL # [BSK] Exchange components

% QpntsRXs

1 | 14 | # [Xs] Transferred momenta

%

% BndsRnXs

1 | 18 | # [Xs] Polarization function bands

%

NGsBlkXs= 1 RL # [Xs] Response block size

% LongDrXs

1.000000 | 0.000000 | 0.000000 | # [Xs] [cc] Electric Field

%

BSSmod= "h" # [BSS] Solvers `h/d/i/t`

% BEnRange

0.00000 | 10.00000 | eV # [BSS] Energy range

%

% BDmRange

0.10000 | 0.10000 | eV # [BSS] Damping range

%

BEnSteps= 100 # [BSS] Energy steps

% BLongDir

1.000000 | 0.000000 | 0.000000 | # [BSS] [cc] Electric Field

%

Then type >yambo -N, it seems to go well .and I got the optical spectrum of it, but this result is the same like the RPA one.The two OAS agree very well. Is the result believable?

The RPA input file is:

optics # [R OPT] Optics

chi # [R CHI] Dyson equation for Chi.

% QpntsRXd

1 | 14 | # [Xd] Transferred momenta

%

% BndsRnXd

1 | 18 | # [Xd] Polarization function bands

%

NGsBlkXd= 1 RL # [Xd] Response block size

% EnRngeXd

0.00000 | 10.00000 | eV # [Xd] Energy range

%

% DmRngeXd

0.10000 | 0.10000 | eV # [Xd] Damping range

%

ETStpsXd= 100 # [Xd] Total Energy steps

% LongDrXd

1.000000 | 0.000000 | 0.000000 | # [Xd] [cc] Electric Field

%

What is the problem??

When I calculate bulk Si, the speed is slow.But my unitcell including 6 atoms is very quick as RPA procedure. I do not know why??

Thanks in advance !!

SDWang

I have calculate my 2D rectangle unitcell including 4C atoms and 2O atoms with pwscf v4.1.2, then I do a BSE calculation.I type >yambo -o b -b -y h,and edit input file as:

optics # [R OPT] Optics

bse # [R BSK] Bethe Salpeter Equation.

em1s # [R Xs] Static Inverse Dielectric Matrix

bss # [R BSS] Bethe Salpeter Equation solver

BSresKmod= "xc" # [BSK] Resonant Kernel mode. (`x`;`c`;`d`)

% BSEBands

1 | 18 | # [BSK] Bands range

%

BSENGBlk= 1 RL # [BSK] Screened interaction block size

BSENGexx= 2027 RL # [BSK] Exchange components

% QpntsRXs

1 | 14 | # [Xs] Transferred momenta

%

% BndsRnXs

1 | 18 | # [Xs] Polarization function bands

%

NGsBlkXs= 1 RL # [Xs] Response block size

% LongDrXs

1.000000 | 0.000000 | 0.000000 | # [Xs] [cc] Electric Field

%

BSSmod= "h" # [BSS] Solvers `h/d/i/t`

% BEnRange

0.00000 | 10.00000 | eV # [BSS] Energy range

%

% BDmRange

0.10000 | 0.10000 | eV # [BSS] Damping range

%

BEnSteps= 100 # [BSS] Energy steps

% BLongDir

1.000000 | 0.000000 | 0.000000 | # [BSS] [cc] Electric Field

%

Then type >yambo -N, it seems to go well .and I got the optical spectrum of it, but this result is the same like the RPA one.The two OAS agree very well. Is the result believable?

The RPA input file is:

optics # [R OPT] Optics

chi # [R CHI] Dyson equation for Chi.

% QpntsRXd

1 | 14 | # [Xd] Transferred momenta

%

% BndsRnXd

1 | 18 | # [Xd] Polarization function bands

%

NGsBlkXd= 1 RL # [Xd] Response block size

% EnRngeXd

0.00000 | 10.00000 | eV # [Xd] Energy range

%

% DmRngeXd

0.10000 | 0.10000 | eV # [Xd] Damping range

%

ETStpsXd= 100 # [Xd] Total Energy steps

% LongDrXd

1.000000 | 0.000000 | 0.000000 | # [Xd] [cc] Electric Field

%

What is the problem??

When I calculate bulk Si, the speed is slow.But my unitcell including 6 atoms is very quick as RPA procedure. I do not know why??

Thanks in advance !!

SDWang