| Re: MD step update and mixing weight; specification or problem? ( No.1 )|
- Date: 2017/08/01 23:11
- Name: T. Ozaki
During MD, the initial charge density at each MD step is obtained by extrapolation using
charge densities at previous steps. So, in many cases the estimated charge density
can be a good approximation for the converged one, and we expect that convergence can be
obtained even using a large mixing weight. That's why Mixing_weight is set to the maximum
However, as you worry, such a treatment may cause charge sloshing problem again for some
cases. For such cases it might be better to use a relatively smaller scf.Max.Mixing.Weight.
If you do not want such a behavior, you only have to comment out the following line
of 905 in DFT.c:
if (MD_iter!=1) Mixing_weight = Max_Mixing_weight;
If you do that, Mixing_weight is not set to Max_Mixing_weight.
| Re: MD step update and mixing weight; specification or problem? ( No.2 )|
- Date: 2017/08/02 12:33
- Name: Asako Terasawa
Thank you for your very helpful answer.
Now I and one of colleague are trying both suggestions and checking the behavior of NormRD and mixing_weight, because we are treating systems which easily diverge.
I will let you know again if I get any suggestive results.