Search found 165 matches

by Vladimir_Konjkov
Sat Sep 03, 2022 4:51 pm
Forum: The CASINO program
Topic: molden2qmc
Replies: 45
Views: 343751

Re: molden2qmc

Greetings to all who use the Casino. I found an issue in the molden2qmc script that shows up in Python version 3.10. Corrections in the next PR - https://github.com/Konjkov/molden2qmc/c ... 0778cd177d
Sincerely, Vladimir
by Vladimir_Konjkov
Mon Jan 31, 2022 3:39 pm
Forum: The CASINO program
Topic: Stat inefficiency
Replies: 7
Views: 16477

Re: Stat inefficiency

Dear Pablo and Neil. Thanks for the answers, I just wanted to quote the article of Dario Bressanini "Implications of the two nodal domains conjecture for ground state fermionic wave functions" which stated that the quality of the HF wave function for four electron atoms can be greatly impr...
by Vladimir_Konjkov
Tue Jan 25, 2022 2:57 pm
Forum: The CASINO program
Topic: Stat inefficiency
Replies: 7
Views: 16477

Re: Stat inefficiency

Yes, I use a [dtdmc, population] sequence that satisfy dtdmc * population = const equation. Since linear term in the power expansion of timestep error has often opposite sign to linear term of finite population error, one can randomly choose such a const which zeros out the linear term of sequence [...
by Vladimir_Konjkov
Tue Jan 25, 2022 4:38 am
Forum: The CASINO program
Topic: Stat inefficiency
Replies: 7
Views: 16477

Re: Stat inefficiency

Thanks Neil for the detailed explanation. if you mean the exponential wall described in the article. "Diffusion Monte Carlo: exponential scaling of computational cost for large systems" of Norbert Nemec, then my system is too small for it - a single beryllium atom. Today when recalculating...
by Vladimir_Konjkov
Sun Jan 23, 2022 7:06 am
Forum: The CASINO program
Topic: Stat inefficiency
Replies: 7
Views: 16477

Stat inefficiency

Hello CASINO developers In one of the calculations I noticed a warning " Warning: [POPSTATS_DUMP] Significant inefficiency due to population correlation. Be sure to understand the implications." and indeed: Target weight = 4267.000000000000 Average population = 4267.373640000001 +/- 0.0684...
by Vladimir_Konjkov
Sun Aug 08, 2021 4:16 am
Forum: Quantum Monte Carlo
Topic: DMC timestep bias asymptotic
Replies: 17
Views: 98548

Re: DMC timestep bias asymptotic

thanks a lot Neil for your answer.
by Vladimir_Konjkov
Sat Aug 07, 2021 5:12 am
Forum: Quantum Monte Carlo
Topic: DMC timestep bias asymptotic
Replies: 17
Views: 98548

Re: DMC timestep bias asymptotic

If you look at Fig. 13 of Umrigar, Nightingale, Runge, J. Chem. Phys. 1993, you will see that it is nearly quadratic near tau=0. I do not know of a theoretical argument for the behaviour of the time-step error. What is the x-scale on your plots? Cyrus Hello Cyrus and everybody usnig QMC methods. In...
by Vladimir_Konjkov
Fri Apr 16, 2021 5:48 pm
Forum: The CASINO program
Topic: backflow issue when C=0
Replies: 7
Views: 42390

Re: backflow issue when C=0

It was a terrible mistake in my code in the function calculating smooth cutoffs around AE atoms.
Thanks everyone for the help.
by Vladimir_Konjkov
Fri Apr 16, 2021 3:38 pm
Forum: The CASINO program
Topic: backflow issue when C=0
Replies: 7
Views: 42390

Re: backflow issue when C=0

Does the output of `plot_backflow` help with your debugging? (See `casinohelp plot_backflow` for info.) Thank you Pablo, I'll try to check right now. My doubts arose from my implementation of eta-term as: def eta_term(self, e_vectors, e_powers): """ :param e_vectors: e-e vectors :par...
by Vladimir_Konjkov
Thu Apr 15, 2021 7:54 am
Forum: The CASINO program
Topic: backflow issue when C=0
Replies: 7
Views: 42390

Re: backflow issue when C=0

Hello Mike. Nice to read you. I am writing a program in python, numpy and numba that reads Casino input files and performs calculations given in INPUT and now I came to BACKFLOW implementation...everything is so terribly complicated there. It seems to me that the ETA term is calculated incorrectly, ...