Search found 113 matches
- Tue Mar 23, 2021 8:59 am
- Forum: The CASINO program
- Topic: Problem obtaining static structure factor
- Replies: 3
- Views: 23730
Re: Problem obtaining static structure factor
Dear Ankush, The structure factor plotted by plot_expval is normalised such that the total structure factor S(k) -> 1 as k->oo, where S(k) = sum_a sum_b S_ab(k), where a and b denote spins. Different normalisation conventions are used in the literature (differing by factors of density N/Omega and ce...
- Mon Mar 22, 2021 9:30 pm
- Forum: The CASINO program
- Topic: Problem obtaining static structure factor
- Replies: 3
- Views: 23730
Re: Problem obtaining static structure factor
Dear Ankush, Thanks for the question. I was wondering if you could clarify what the problem is? I've just tried running a harmonic wire VMC calculation and I can't see any problem with the static structure factor. I calculated the structure factor by setting structure_factor to T in the input file, ...
- Sun May 17, 2020 10:35 am
- Forum: The CASINO program
- Topic: About dtvmc and PCF
- Replies: 1
- Views: 29747
Re: About dtvmc and PCF
Dear Ankush, Usually the VMC time step is automatically optimised by choosing it such that the VMC move-acceptance probability is 50%. This is the default behaviour, unless you have set opt_dtvmc to 0 in the input file. If you want to check that your VMC time step is OK, check that the overall accep...
- Mon May 04, 2020 3:02 pm
- Forum: The CASINO program
- Topic: Autotest for cutoffs optimization
- Replies: 10
- Views: 65678
Re: Autotest for cutoffs optimization
Dear Vladimir & Pablo, You're right: I broke gjastrow optimisation in the patch that Pablo indicated. I've just sent a patch fixing the issue to Mike. Thanks very much for pointing out the problem, and I'm very sorry about the inconvenience. The above results of playing around with the pjastrow ...
- Sun May 03, 2020 8:22 am
- Forum: The CASINO program
- Topic: Autotest for cutoffs optimization
- Replies: 10
- Views: 65678
Re: Autotest for cutoffs optimization
Dear Vladimir,
The form of Jastrow that you are using is essentially the same that I used: the three terms in your Jastrow factor are u (homogeneous electron-electron), chi (electron-nucleus) and f (electron-electron-nucleus).
Best wishes,
Neil.
The form of Jastrow that you are using is essentially the same that I used: the three terms in your Jastrow factor are u (homogeneous electron-electron), chi (electron-nucleus) and f (electron-electron-nucleus).
Best wishes,
Neil.
- Sat May 02, 2020 10:22 pm
- Forum: The CASINO program
- Topic: Autotest for cutoffs optimization
- Replies: 10
- Views: 65678
Re: Autotest for cutoffs optimization
Dear Both, Optimisation of cutoff lengths has always been challenging and numerically sensitive. These days I tend to fix the cutoff lengths at sensible values rather than attempt to optimise them. In the present case, fixing L_u=10, L_chi=8 and L_f=7 a.u. works OK: VMC #1: E = -24.588(2) ; var = 0....
- Fri May 01, 2020 8:08 pm
- Forum: The CASINO program
- Topic: Autotest for cutoffs optimization
- Replies: 10
- Views: 65678
Re: Autotest for cutoffs optimization
Dear Vladimir, Here's a very quick test. For a 27-electron r_s=4 3D electron gas with a Jastrow factor containing a U term only, if I start from a cutoff length of L =4 a.u. and optimise the linear parameters together with the cutoff using variance minimisation: VMC #1: E = -0.0497(1) ; var = 1.30(4...
- Sun Apr 26, 2020 5:44 pm
- Forum: The CASINO program
- Topic: New required citation for publications using CASINO
- Replies: 3
- Views: 28161
Re: New required citation for publications using CASINO
Thanks very much!
Neil.
Neil.
- Wed Apr 22, 2020 12:27 pm
- Forum: The CASINO program
- Topic: New required citation for publications using CASINO
- Replies: 3
- Views: 28161
New required citation for publications using CASINO
Dear All, Hope you are safe and well during the coronavirus pandemic. There is a new required citation for publications that use the CASINO software: R. J. Needs, M. D. Towler, N. D. Drummond, P. Lopez Rios and J. R. Trail, Variational and diffusion quantum Monte Carlo calculations with the CASINO c...
- Wed Aug 28, 2019 2:50 pm
- Forum: The CASINO program
- Topic: Errors during casino installation (v2.13.802-1-g198d8d47)
- Replies: 3
- Views: 34982
Re: Errors during casino installation (v2.13.802-1-g198d8d47
Mike has now made the update.
Best wishes,
Neil.
Best wishes,
Neil.