[Pw_forum] Fermi Energy and DOS

[degironc]

are you using the dos.f90 program in PP ?
Integration is made with a very poor algorithm ... I would not trust it 
of  deltaE is large .
Try to reduce deltaE and see if results improves
stefano

xshen wrote:

>Hi:
>
>I am doing calculation of DOS of a supercell system. I did the scf
>calculation first and then a nscf calculation for the DOS. The scf and
>nscf calculations give me similar value of Fermi energy. however when I
>checked  the total DOS state, I found that the  "Int dos" at the given
>Fermi energy is not equal to the total number of electrons in my system.
> Should I use the Fermi energy the program gives me, or pick the energy
>where the "Int dos" is equal to my # of electrons?
>
>The data is here .
>scf calculation gives : Fermi energy is    -0.3788 ev
>nscf calculation gives : Fermi energy is    -0.3892 ev
>
>My system has 234 electrons, however at E= -0.4, the INT dos is 225.2.
>If I want INT dos =234, the energy is between 2.500 and 2.600 ev.
>
>Part of the Dos file:
>
>#  E (eV)   dos(E)     Int dos(E)
> -0.500  0.8034E-83  0.2252E+03
> -0.400  0.2168E-78  0.2252E+03
> -0.300  0.3285E-41  0.2252E+03
> -0.200  0.9263E-16  0.2252E+03
> -0.100  0.4941E-02  0.2252E+03
>  0.000  0.2989E+01  0.2255E+03
>  0.100  0.1309E+01  0.2256E+03
>  0.200  0.5846E+00  0.2257E+03
>  0.300  0.9425E+00  0.2258E+03
>  0.400  0.9223E+00  0.2259E+03
>  0.500  0.5458E+00  0.2259E+03
>  0.600  0.1596E+00  0.2259E+03
>  0.700  0.4433E-01  0.2259E+03
>  0.800  0.2465E+00  0.2260E+03
>  0.900  0.1201E+01  0.2261E+03
>  1.000  0.2066E+01  0.2263E+03
>  1.100  0.9347E+00  0.2264E+03
>  1.200  0.1511E+00  0.2264E+03
>  1.300  0.8143E+01  0.2272E+03
>  1.400  0.4891E+01  0.2277E+03
>  1.500  0.4694E+01  0.2282E+03
>  1.600  0.4475E+01  0.2286E+03
>  1.700  0.2586E+01  0.2289E+03
>  1.800  0.1381E+01  0.2290E+03
>  1.900  0.2355E+01  0.2293E+03
>  2.000  0.3072E+01  0.2296E+03
>  2.100  0.3584E+01  0.2299E+03
>  2.200  0.4034E+01  0.2303E+03
>  2.300  0.4071E+01  0.2307E+03
>  2.400  0.1592E+02  0.2323E+03
>  2.500  0.1043E+02  0.2334E+03
>  2.600  0.9686E+01  0.2343E+03
>  2.700  0.7500E+01  0.2351E+03
>  2.800  0.4397E+01  0.2355E+03
>
>
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