Search found 165 matches

by Vladimir_Konjkov
Tue Jun 30, 2015 6:47 am
Forum: The CASINO program
Topic: Optimized decorrelation period
Replies: 3
Views: 9715

Re: Optimized decorrelation period

Hi all. I recently read the manual p.25.1 Variance minimization: the standard method it says that: It is clearly desirable for the VMC-generated configurations to be completely uncorrelated. This can be achieved by giving vmc_decorr_period a large value (e.g., 10). Reblocking VMC energies in a preli...
by Vladimir_Konjkov
Wed Jun 17, 2015 4:01 am
Forum: The CASINO program
Topic: Cutoff lengths in the Jastrow factor
Replies: 12
Views: 31246

Re: Cutoff lengths in the Jastrow factor

Hi, all. I find that main disadvantage of Jastrow optimisation in finite system (molecule) that it's poorly describe inhomogeneity of electron density. In Casino implementation, the only way to take the inhomogeneity into account is to introduce sets of different Jastrow parameters and cutoff the ar...
by Vladimir_Konjkov
Thu Jun 04, 2015 12:12 pm
Forum: The CASINO program
Topic: Equilibration vs statistics accumulation steps in DMC
Replies: 6
Views: 13997

Re: Equilibration vs statistics accumulation steps in DMC

For example, do you know why some programs can not converge f-ane test to lower energy state with broken symmetry but other can? not always programs automatically select the best way to converge, but by hands I can do better, unless of course if it is allowed to do something by hands. You know, of ...
by Vladimir_Konjkov
Wed Jun 03, 2015 1:23 pm
Forum: The CASINO program
Topic: molden2qmc
Replies: 45
Views: 343271

Re: molden2qmc

I downloaded the trial version of MOLPRO, once again was shocked by originality of conversion algorithm from cartesian to the spherical basis. :shock:
RHF case works.
UHF case - two input MOLPRO files generated, oh my god, MOLPRO developers do not like simple solutions.
by Vladimir_Konjkov
Wed Jun 03, 2015 12:46 am
Forum: The CASINO program
Topic: molden2qmc
Replies: 45
Views: 343271

Re: molden2qmc

I added support for Dalton2013 in molden2qmc script version 2.5.2, available from https://github.com/Konjkov/molden2qmc. Two bad news: In Dalton's MOLDEN file all occupation numbers of HF and DFT MOs are zero values by mistake. You should correct 'Number of electrons per primitive cell' in gwfn.data...
by Vladimir_Konjkov
Mon Jun 01, 2015 4:06 pm
Forum: The CASINO program
Topic: Equilibration vs statistics accumulation steps in DMC
Replies: 6
Views: 13997

Re: Equilibration vs statistics accumulation steps in DMC

Hi Vladimir, Som aspects of these questions are addressed in my talk from last years TTI conference: http://www.tcm.phy.cam.ac.uk/~mdt26/tti_talks/qmcitaa_14/towler_tti2014.pdf Have a read of that and let me know what you think - see the stuff about empirical convergence at the end.. I accidentally...
by Vladimir_Konjkov
Mon Jun 01, 2015 9:24 am
Forum: The CASINO program
Topic: Equilibration vs statistics accumulation steps in DMC
Replies: 6
Views: 13997

Re: Equilibration vs statistics accumulation steps in DMC

Hi Vladimir, For the stuff about Gaussian noise, see John Trails two papers about the central limit theorem etc.. Mike Hi, Mike http://journals.aps.org/pre/abstract/10.1103/PhysRevE.77.016703 http://journals.aps.org/pre/abstract/10.1103/PhysRevE.77.016704 The articles are very helpful, they answere...
by Vladimir_Konjkov
Sun May 31, 2015 9:12 am
Forum: The CASINO program
Topic: Equilibration vs statistics accumulation steps in DMC
Replies: 6
Views: 13997

Equilibration vs statistics accumulation steps in DMC

Hi, all. CASINO suggests that the DMC calculation is as follows: We do n1 - equilibration steps, and then n2 - statistics accumulation steps. So OK, let's assume that DMC energy - E (n) depends on step number - n as follows: E(n) = E(infinity) * (1 + exp(-alpha*n)) + Noise(n) where: (1 + exp(-alpha*...
by Vladimir_Konjkov
Thu May 21, 2015 7:28 am
Forum: The CASINO program
Topic: Pseudopotential problems
Replies: 2
Views: 9710

Re: Pseudopotential problems

To make life easier for ORCA users, I create files with ECP and aug-cc-pVXZ-CDF bases in ORCA format for all available elements. DF_AREP_Trail_Needs_gamess.bas - DF AREP Trail Needs ECP basis generated from gamess one ('slightly worse' representation) DF_AREP_Trail_Needs_gaussian.bas - DF AREP Trail...
by Vladimir_Konjkov
Sun May 17, 2015 3:35 pm
Forum: The CASINO program
Topic: Calculation of forces in QMC
Replies: 15
Views: 44991

Re: Calculation of forces in QMC

It seems that I forgot to change the valence charge of C atom from 6 to 4 (my script molden2qmc does not perform it), but despite this the presence of c_pp.data and h_pp.data files initiated casino to perform calculations with a pseudopotential. Energy obtained agrees with that from ORCA with same p...