Search found 26 matches

by Ryan_Hunt
Fri Mar 09, 2018 2:19 pm
Forum: The CASINO program
Topic: N2 DMC energy is better then exact
Replies: 10
Views: 28862

Re: N2 DMC energy is better then exact

(all this to say, in this case, I think we might also want to scrutinise the "exact" result as well as we do the DMC result)
by Ryan_Hunt
Fri Mar 09, 2018 2:16 pm
Forum: The CASINO program
Topic: N2 DMC energy is better then exact
Replies: 10
Views: 28862

Re: N2 DMC energy is better then exact

Pablo, That's right - however, this value was pieced together from various other places. Some portions of it (vibrational zero point energy, scalar relativistic corrections) are from different theoretical calculations (which presumably have some uncertainties) and one portion of it (the atomisation ...
by Ryan_Hunt
Fri Mar 09, 2018 1:52 pm
Forum: The CASINO program
Topic: N2 DMC energy is better then exact
Replies: 10
Views: 28862

Re: N2 DMC energy is better then exact

Vladimir, Thanks for your reply. I'm having a hard time chasing up what exactly has gone into the "exact energy" quoted in the earlier referenced PRE. For example, can you find where the experimental atomization energy of N_2 used to form the electronic ground state energy actually came fr...
by Ryan_Hunt
Fri Mar 09, 2018 12:33 pm
Forum: The CASINO program
Topic: N2 DMC energy is better then exact
Replies: 10
Views: 28862

Re: N2 DMC energy is better then exact

Vladimir, I'm not sure what you are asking here. You're ground state energy is: -109.542(1) a.u., whilst the exact value (from Ref. 38 of the quoted PRE article) is -109.5421 a.u. These two are consistent with each other (at the level of statistical significance you are working), and your VMC energy...
by Ryan_Hunt
Fri Sep 08, 2017 3:59 pm
Forum: The CASINO program
Topic: Changing decorr length in vmc for varmin_linjas and emin?!
Replies: 19
Views: 38606

Re: Changing decorr length in vmc for varmin_linjas and emin

Katharina, Ahhhhh! That (a) makes sense and is (b) obviously bad! Removing that pair of if statements should be safe for now. Perhaps in the long-term that block of code should be protected from re-executing, maybe by wrapping it in a conditional which is satisfied only for the first opt. cycle? Per...
by Ryan_Hunt
Fri Sep 08, 2017 1:58 pm
Forum: The CASINO program
Topic: Changing decorr length in vmc for varmin_linjas and emin?!
Replies: 19
Views: 38606

Re: Changing decorr length in vmc for varmin_linjas and emin

Katharina, I have looked a little bit for those kind of statements, however, I think the problem is one specifically affecting the first vmc run when the runtype is 'vmc_opt'. Grepping about for "if" statements involving opt_cycle didn't lead me to anything that seems relevant, though... I...
by Ryan_Hunt
Fri Sep 08, 2017 1:12 pm
Forum: The CASINO program
Topic: Changing decorr length in vmc for varmin_linjas and emin?!
Replies: 19
Views: 38606

Re: Changing decorr length in vmc for varmin_linjas and emin

Katharina,

I think you are correct. I'll make these changes and run my tests. I had spotted the oddity in line 661 of monte_carlo.f90 last night, intending to investigate further today. Unfortunately I haven't had time, but happily you seem to have done this detective work already.

Regards,
Ryan.
by Ryan_Hunt
Thu Sep 07, 2017 3:10 pm
Forum: The CASINO program
Topic: Changing decorr length in vmc for varmin_linjas and emin?!
Replies: 19
Views: 38606

Re: Changing decorr length in vmc for varmin_linjas and emin

Katharina, I don't think it should affect the calculations, however, that would assume no bugs. In my tests, if I manually set vmc_decorr_period to 3 (i.e. to the same as corper_default_vmc), and I repeat the tests from scratch, I find that correlation times agree (within uncertainties).... Regards,...
by Ryan_Hunt
Thu Sep 07, 2017 2:49 pm
Forum: The CASINO program
Topic: Changing decorr length in vmc for varmin_linjas and emin?!
Replies: 19
Views: 38606

Re: Changing decorr length in vmc for varmin_linjas and emin

Katharina, Yes, I can reproduce the issue. Moreover, it doesn't seem specifically dependant on using emin in the second stage. Identical (disagreeing with the output of the varmin_linjas final VMC run) correlation times are found regardless of the new opt_method. Even if the new opt_method is varmin...
by Ryan_Hunt
Thu Sep 07, 2017 1:18 pm
Forum: The CASINO program
Topic: Changing decorr length in vmc for varmin_linjas and emin?!
Replies: 19
Views: 38606

Re: Changing decorr length in vmc for varmin_linjas and emin

Issue also affects AE calculations...