Search found 95 matches

by Neil Drummond
Sun Jan 08, 2017 11:58 am
Forum: The CASINO program
Topic: runqmc stops without any error.
Replies: 7
Views: 19103

Re: runqmc stops without any error.

Dear Rajesh, Note that you are using the same two-body terms between pairs of electrons and between electrons and holes. Since the electrons and holes have the same mass, it would be best to define a custom spin dependence with the pair groupings (1-1,2-2) and (1-2). Alternatively you could set the ...
by Neil Drummond
Sun Jan 08, 2017 11:38 am
Forum: The CASINO program
Topic: runqmc stops without any error.
Replies: 7
Views: 19103

Re: runqmc stops without any error.

Dear Rajesh, I am running your example on four cores with the same random seed as you... I've got to 69 cycles so far without problems (see attached out file). If you diff the out file with yours you will see that the first VMC calculation is exactly the same. After that differences creep in, becaus...
by Neil Drummond
Wed Nov 02, 2016 10:24 pm
Forum: The CASINO program
Topic: The blip trial wave function
Replies: 7
Views: 17199

Re: The blip trial wave function

Dear Nguyen, The error message means that the number of available orbitals is less than the the number of spin-up or spin-down electrons - which obviously isn't going to work. Perhaps you should show your Quantum Espresso input files and the CASINO input file on the forum, and someone familiar with ...
by Neil Drummond
Tue Nov 01, 2016 4:04 pm
Forum: The CASINO program
Topic: The blip trial wave function
Replies: 7
Views: 17199

Re: The blip trial wave function

Dear Nguyen, I think your question 3 is simply about re-representing your Bloch orbitals in a blip basis? If so, you don't need to provide centres.dat. (Note that using a localised basis set, e.g., blips, is a separate issue from transforming your Bloch orbitals to a set of localised orbitals. As Ka...
by Neil Drummond
Tue Oct 25, 2016 4:51 pm
Forum: The CASINO program
Topic: Calc. dying with memory issues after exec. of several blocks
Replies: 5
Views: 10032

Re: Calc. dying with memory issues after exec. of several bl

Dear Katharina, Thanks very much for reporting the issue - I agree there is a memory problem. It seems to have been introduced in patch 1d6d14ae, in which the call to dmc_annihilate_configs at the end of dmc_main was bypassed for the equilibration stage of a DMC calculation. This means that the data...
by Neil Drummond
Tue Oct 25, 2016 12:28 pm
Forum: The CASINO program
Topic: Calc. dying with memory issues after exec. of several blocks
Replies: 5
Views: 10032

Re: Calc. dying with memory issues after exec. of several bl

Dear Katharina, Sorry to hear about the memory problems. a) CASINO allocates configurations when they are born and deallocates them when they die, so the memory requirements fluctuate in time. The details of memory management are handled by the compiler and we have to hope that it is sensible. Perha...
by Neil Drummond
Thu Aug 04, 2016 4:49 pm
Forum: Quantum Monte Carlo
Topic: DMC energy
Replies: 21
Views: 34321

Re: DMC energy

P.S. I think the most likely reason for the apparent disagreement in the DMC results with different Jastrows is the need for a better treatment of population-control errors in the no-Jastrow case. I suggest varying the target weight in inverse proportion to the time step.
by Neil Drummond
Thu Aug 04, 2016 4:39 pm
Forum: Quantum Monte Carlo
Topic: DMC energy
Replies: 21
Views: 34321

Re: DMC energy

Dear Fan et al., A few quick comments: * The all-electron DMC energies obtained with different Jastrow factors ought to agree so long as time step bias is controlled, population-control bias is controlled and the equilibration period is long enough. * The Bohr radius of oxygen is 1/8 a.u., suggestin...
by Neil Drummond
Thu Jul 07, 2016 9:25 am
Forum: Jobs
Topic: Chair and Senior Lectureship in Condensed Matter Theory
Replies: 0
Views: 16104

Chair and Senior Lectureship in Condensed Matter Theory

The Department of Physics at Lancaster University seeks to appoint a full-time Chair and a full-time Senior Lecturer to enhance and complement our thriving activities in theoretical condensed matter physics. We are looking for candidates with an outstanding research profile in areas such as strongly...
by Neil Drummond
Mon Jul 04, 2016 2:37 pm
Forum: The CASINO program
Topic: varmin, varmin-linjas
Replies: 8
Views: 12133

Re: varmin, varmin-linjas

... that was why I mentioned the possibility of jumping out of a local minimum, which varmin_linjas, but not varmin, can do.

However, I think this is all a long elaboration on my original answer of, "I don't know"!

Thanks,

Neil.