Search found 95 matches

by Neil Drummond
Wed Apr 22, 2020 12:27 pm
Forum: The CASINO program
Topic: New required citation for publications using CASINO
Replies: 3
Views: 7963

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...
by Neil Drummond
Wed Aug 28, 2019 2:50 pm
Forum: The CASINO program
Topic: Errors during casino installation (v2.13.802-1-g198d8d47)
Replies: 3
Views: 14492

Re: Errors during casino installation (v2.13.802-1-g198d8d47

Mike has now made the update.

Best wishes,

Neil.
by Neil Drummond
Wed Aug 28, 2019 12:30 pm
Forum: The CASINO program
Topic: Errors during casino installation (v2.13.802-1-g198d8d47)
Replies: 3
Views: 14492

Re: Errors during casino installation (v2.13.802-1-g198d8d47

Dear Rajesh, Thanks very much for reporting this. The problem is that a couple of source files used by utilities have been renamed in the version that you are using, causing the utilities to fail to compile. I've sent a fix to Mike and hopefully the standard version of CASINO will be updated soon. B...
by Neil Drummond
Sun Oct 07, 2018 10:17 am
Forum: The CASINO program
Topic: CASINO publications...
Replies: 0
Views: 10303

CASINO publications...

Dear All, To support a grant application, I am trying to identify all the publications that have used CASINO. Please see the list at http://www.lancaster.ac.uk/staff/drummonn/casino_papers.html If you have published a paper using CASINO then please check the list and let me know of any errors or omi...
by Neil Drummond
Sun Oct 07, 2018 10:08 am
Forum: The CASINO program
Topic: spin symmetry in the Jastrow factor
Replies: 3
Views: 12518

Re: spin symmetry in the Jastrow factor

Dear Alan, I would have expect the "spin-polarised" wave function to be in principle just as good as the non-spin-polarised wave function. In practice it would be slightly more difficult to optimise the redundant parameters. So I think something must be wrong in the case you describe, but ...
by Neil Drummond
Sun Oct 07, 2018 10:04 am
Forum: The CASINO program
Topic: compiler errors - not accepting certain directives
Replies: 1
Views: 9472

Re: compiler errors - not accepting certain directives

Dear Alan,

I was wondering if you could give more information about the version of GCC that you are using?

If necessary you can create a new CASINO_ARCH to avoid the problematic compiler flags.

Thanks,

Neil.
by Neil Drummond
Fri May 25, 2018 8:31 am
Forum: Quantum Monte Carlo
Topic: DMC timestep bias asymptotic
Replies: 14
Views: 42823

Re: DMC timestep bias asymptotic

Dear Vladimir,

Thanks very much for investigating this.

The slope at tau=0 is b-D.a, so setting b=0 doesn't get rid of the slope at tau=0 (but I can nevertheless believe that setting b=0 gives a reasonable fitting function for the situation you describe).

Best wishes,

Neil.
by Neil Drummond
Thu May 24, 2018 12:49 pm
Forum: Quantum Monte Carlo
Topic: DMC timestep bias asymptotic
Replies: 14
Views: 42823

Re: DMC timestep bias asymptotic

Thanks for sending the graph. I think I'll stick to plane waves and pseudopotentials...

Best wishes,

Neil.
by Neil Drummond
Thu May 24, 2018 9:03 am
Forum: Quantum Monte Carlo
Topic: DMC timestep bias asymptotic
Replies: 14
Views: 42823

Re: DMC timestep bias asymptotic

In these cases, instead of fitting a+b.tau^(1/2)+c.tau... to the DMC energy, it might be better to fit (a+b.tau+c.tau^2)/(1+D.tau) to the energy against time step tau. This describes a crossover between two different linear bias regimes.

Best wishes,

Neil.
by Neil Drummond
Fri Mar 16, 2018 9:44 am
Forum: Quantum Monte Carlo
Topic: DMC timestep bias asymptotic
Replies: 14
Views: 42823

Re: DMC timestep bias asymptotic

Dear Vladimir, You are certainly right that the behaviour around nuclei makes a big difference to the finite time-step behaviour. Cyrus Umrigar's modifications to the DMC Green's functions [Umrigar, Nightingale and Runge, JCP 99 , 2865, (1993)] impose the cusp-like behaviour around nuclei at finite ...