The ABINIT Users Mailing List ( CLOSED )

["Haverty, Michael G" <michael.g.haverty@intel.com>]

Hi all,

I’m trying to validate Ab-init for conductivity calculations, but the conducti (tests/v3/t78.in and tests/v3/t79.in) results aren’t converging to one conductivity value.  From the CRC handbook the experimental Al conductivity at 300K is 4.13 X 10^5 (Ohm-cm)^5.  

I’m finding that if I change the sampling of omega when using conducti, my value for Al conductivity (near omega=0) changes by orders of magnitude (from 4.13 X 10^6 to 4.15 X 10^4 for omega sampling from 0.00001 to 0.001).  I’m using a 1-atom supercell, with 20 bands, 40 Hartree energy cutoff,  and 12x12x12 k-point sampling, but have seen similar variability of the conductivity for less dense k-point samplings as well.

From the standard output of the conducti code, I don’t understand what the line “sumrule” means.  For example, my output of this line is:

            sumrule           =   1.24920   2.93610

From the src/main/conducti.f90 file, I see that this output is coming from the following line, but I don’t understand what np_sum and socc signify:

write(6,'(a,3f10.5)')' sumrule           =',np_sum/socc/3.0d0,socc

            To ensure that sum rule evaluation is as close to 1 as possible, which of these 2 results “1.24920” or “2.93610” should we monitor to ensure it is as close to 1 as possible?  Also, what setting of the t78.in (t78.in is the abinit run for self-consistency and DDB, WFK generation) will affect the value of the sum rule?

Can anyone recommend what I should do to get a well-converged conductivity to compare against the experimental data?

                                                Mike