This shows you the differences between two versions of the page.
Both sides previous revision Previous revision | Next revision Both sides next revision | ||
band_structure [2012/11/30 10:16] dani |
band_structure [2014/02/09 11:24] dani |
||
---|---|---|---|
Line 97: | Line 97: | ||
{{:si-bulk:pdos-si_bulk.png?400|DOS Si Bulk}} | {{:si-bulk:pdos-si_bulk.png?400|DOS Si Bulk}} | ||
- | |||
- | ===== The bulk modulus ===== | ||
- | |||
- | $ ls | ||
- | Fdata uno.bas uno.kpts uno.lvs vol.sh | ||
- | | ||
- | $ head uno.bas | ||
- | 2 | ||
- | 14 0.000000 0.000000 0.000000 | ||
- | 14 0.250000 0.250000 0.250000 | ||
- | | ||
- | $ head uno.kpts | ||
- | 32 | ||
- | -2.35619449 -2.35619449 -2.35619449 0.03125000 | ||
- | -3.92699081 -0.78539816 -0.78539816 0.03125000 | ||
- | -5.49778713 0.78539816 0.78539816 0.03125000 | ||
- | -7.06858347 2.35619449 2.35619449 0.03125000 | ||
- | -0.78539816 -3.92699081 -0.78539816 0.03125000 | ||
- | -2.35619449 -2.35619449 0.78539816 0.03125000 | ||
- | -3.92699081 -0.78539816 2.35619449 0.03125000 | ||
- | -5.49778713 0.78539816 3.92699081 0.03125000 | ||
- | 0.78539816 -5.49778713 0.78539816 0.03125000 | ||
- | | ||
- | $ head uno.lvs | ||
- | 0.5000 0.5000 0.0000 | ||
- | 0.5000 0.0000 0.5000 | ||
- | 0.0000 0.5000 0.5000 | ||
- | |||
- | The script to calculate the bulk modulus | ||
- | $ cat vol.sh | ||
- | #!/bin/bash | ||
- | |||
- | ##----- Parametros de control (el parametro de red tiene que encontrase entre ini fin --------## | ||
- | N=10 | ||
- | ini=5.0 | ||
- | fin=6.0 | ||
- | |||
- | ##----------Funcion analisis para dos atomos/celda-----------------------------------------## | ||
- | function analisis { | ||
- | ETOT=$(grep 'ETOT' salida.out|cut -d'=' -f2) | ||
- | sigma=$(grep sigma salida.out | cut -d'=' -f16 | tail -1) | ||
- | charge=$(head -2 uno.bas | tail -1 | tr -s ' ' | cut -d' ' -f2)' -> '$(head -2 CHARGES | tail -1) | ||
- | charge=$charge' ;'$(head -3 uno.bas | tail -1 | tr -s ' ' | cut -d' ' -f2)' -> ' | ||
- | charge=$charge$(tail -1 CHARGES) | ||
- | echo $rescal$'\t'$ETOT$'\t'$sigma$'\t'$charge$'\t'>>salida | ||
- | } | ||
- | ##------------------------------------------------------------------------------------------## | ||
- | function start { | ||
- | rm -fr salida | ||
- | for((i=0;i<=N;i++)) | ||
- | do | ||
- | rescal=$(python -c "print '%.6f' % ($i*1.0*($fin-$ini)/$N+$ini)") | ||
- | echo "&option | ||
- | basisfile = uno.bas | ||
- | lvsfile = uno.lvs | ||
- | kptpreference = uno.kpts | ||
- | rescal = $rescal | ||
- | sigmatol = 0.000001 | ||
- | nstepf = 1 | ||
- | &end | ||
- | &output | ||
- | iwrtxyz = 1 | ||
- | &end" > fireball.in | ||
- | ../progs/fireball.x > salida.out | ||
- | | ||
- | analisis | ||
- | done | ||
- | } | ||
- | ##----------------------------------1º start ----------------------------------------------## | ||
- | start | ||
- | ##-----------------------------buscamos el minimo ------------------------------------------## | ||
- | min=$(python -c " | ||
- | x0 = [] | ||
- | y0 = [] | ||
- | for line in file(\"salida\"): | ||
- | line = line.split() | ||
- | x = line[0] | ||
- | y = line[1] | ||
- | x0.append(x) | ||
- | y0.append(y) | ||
- | | ||
- | j=0 | ||
- | for i in range(len(x0)): | ||
- | if y0[j]< y0[i]: | ||
- | j=i | ||
- | print x0[j]") | ||
- | cp salida borrar | ||
- | rm -fr aux.py | ||
- | | ||
- | ##----------------------------------2º start -----------------------------------------------## | ||
- | N=40 | ||
- | d=0.4 | ||
- | ini=$(python -c "print '%.6f' % (1.0*($min-$d))") | ||
- | fin=$(python -c "print '%.6f' % (1.0*($min+$d))") | ||
- | start | ||
- | mv salida Vol.dat | ||
- | ##------------------------------------------------------------------------------------------## | ||
- | |||
- | In the 1º start of the script "vol.sh" takes 10 points between 5-6: | ||
- | |||
- | {{:bulk-si-10.png|}} | ||
- | |||
- | In the 2º start of the script "vol.sh" takes 40 points between the minimum of the 1º start | ||
- | |||
- | {{:si-bulk-40.png|}} | ||
- | |||
- | The scripts uses the parameter rescal in fireball.in and unitary positions and lattice vectors with 2 atoms/cell | ||
- | to obtain the kpts points we used xeo: | ||
- | |||
- | {{:xeo-menu-kpts.png|}} | ||
- | |||
- | {{:xeo-kpts.png|}} | ||
- | |||
- | The bulk mudulus can be calculed also with xeo (Utilities->Bulk modulus), in the in line command: | ||
- | |||
- | $ xeo -Bulk Vol.dat zincblende | ||
- | E_min = -214.35239 eV | ||
- | a_min = 5.43719 angs | ||
- | Volumen = 40.18518 ang**3 | ||
- | Bulk modulus = 100.79399 GPa | ||