[Pw_forum] degauss in DOS calculation.

[Jiayu Dai]

Dear users,

Recently, when i was calculating the DOS at finite temperature, i raised a doubt
about it. As we know, the ngauss and degauss value in the input file of dos.x is
important for the results. After the MD calculation at finite temperature, I did
not know if we should use the same value in the scf calculation or MD calculation,
that is, the electronic temperature. When
temperature is low, .ie., lower than 0.2eV, the proplem is not important, because
we can use a small smearing degauss value and the influence is small, regarding to
the small value 0.2/13.6=0.015. However, when the temperaure is increasing, the
value should also increase. My question is if we will use the same value of ngauss
and degauss as in SCF file at high temperature? For example, when temperaure is 10
eV, i used smearing='fermi-dirac' and degauss=0.735 in MD and scf calculations.
Then, if i used different nagauss and degauss values in DOS calculation, the
results are very different. I am confused totally. The degauss represents the same
meaning in SCF?

Thanks in advance.

Jiayu