[Wien] About mixing again

liyh lyhua at fudan.edu.cn
Wed Mar 2 03:22:41 CET 2005

Dear Peter, 
      I am not very clear about mixing.
Does the mixing influence the converged results?
Or, does different mixing parameters can induce diffrent converged results?
For example,
if we set the converging condition as :ENE=0.0001Ry
then we use diffrent mixing parameters.
such as 0.1 or 0.01,
then these two setting can get the same results?

Best Regards


>Did you "correct " case.in1. Do not use -in1new, but restore the old in1
>file (manually).
>You will have almost the same fluctuations for the 36 atom cell, so you must
>have done something strange for the other case.
>When PRATT is very small, the density (potential) must be identical to
>the previous iteration and it should run. Of course, at some point you
>need to increase the mixing, because otherwise you will never reach
>> I also try it as you said, using PRATT and a very small mixing, but it still 
>> failed. I found for a superlattice including 36 atoms, when we use PRATT and 0.01 mixing 
>> parameters, we still can get a converged result, but for 48 atoms's superlattice it failed
>> even we set the parameter to 0.00001. 
>> By the way, when we ask the core level converged to 0.00001Ry which parameters are important.
>For which "super-experiment" do you need a core-level accuracy of 0.1 meV ???
>When you compare with experiment, you will see much larger differences
>Continue your scf cycle (with better -cc or -ec limits) until
>your core-eigenvalue stays constant the way you like it.
>                                      P.Blaha
>Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
>Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
>Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
>Wien mailing list
>Wien at zeus.theochem.tuwien.ac.at

= = = = = = = = = = = = = = = = = = = =

        lyhua at fudan.edu.cn

More information about the Wien mailing list