Search found 138 matches

by Vladimir_Konjkov
Fri Mar 09, 2018 6:27 am
Forum: Quantum Monte Carlo
Topic: DMC timestep bias asymptotic
Replies: 14
Views: 42723

DMC timestep bias asymptotic

Hello everyone who does DMC calculations. I calculated the time step bias dependence for simple full electron systems like H-Cl atoms and some diatomic. I've found that small time step asymptotic is rather quadratic than linear whereas large time step asymptotic is linear in some cases. For example ...
by Vladimir_Konjkov
Thu Jan 18, 2018 8:15 am
Forum: The CASINO program
Topic: Cartesian vs spherical gaussian WFN representation
Replies: 0
Views: 11650

Cartesian vs spherical gaussian WFN representation

Hello CASINO developers. I wonder why the CASINO uses a spherical representation for the gaussian basic functions, while the сartesian representation requires a smaller number of computations to find both the values, derivatives and Laplacian etc. There is no difference only for S and P the orbitals...
by Vladimir_Konjkov
Sat Jan 06, 2018 1:37 am
Forum: The CASINO program
Topic: backflow to the g-orbitals
Replies: 17
Views: 37928

Re: backflow to the g-orbitals

Vladimir_Konjkov wrote: Yes, I also wanted to improve significantly your inelegant code, and compiled profiling version that gave me 'empty' gmon.out.
FFLAGS_prof = -pg -no-pie fix generation of the gmon.out
Also mpif90 is the deprecated OpenMPI wrapper in favor of mpifort.
by Vladimir_Konjkov
Thu Jan 04, 2018 9:21 am
Forum: The CASINO program
Topic: backflow to the g-orbitals
Replies: 17
Views: 37928

Re: backflow to the g-orbitals

Hello Mike. In the gm2_bf SUBROUTINE evaluates the elements of the prim array in CASE of g-orbitals, it seems to me that in this function such calculations are not required. I apologize, I just automatically made the code review. Some guy tried to do that once to the Gaussian evaluators (he was talk...
by Vladimir_Konjkov
Wed Jan 03, 2018 11:51 am
Forum: The CASINO program
Topic: Accelerated Metropolis Method
Replies: 1
Views: 10364

Accelerated Metropolis Method

Hello all It is well known that for effective DMC calculation one need, among other things, to choose the optimal time-step. Fort all-electron atomic systems, the linear regime to occur for time steps less than of the order τ= 1/(3Z^2), where Z is the largest atomic number occurring in the system. h...
by Vladimir_Konjkov
Tue Jan 02, 2018 3:19 pm
Forum: The CASINO program
Topic: backflow to the g-orbitals
Replies: 17
Views: 37928

Re: backflow to the g-orbitals

Hello Mike

Additionally try to change the next line from dg(4,0)/dx, dg(4,0)/dy, dg(4,0)/dz code:

t14=6.d0*xx*(alphay2+fouralphaz2-1.d0) to t14=6.d0*xx*(alphay2-fouralphaz2-1.d0)

This helps the 'g-ane' example to pass the the numerical check of the analytic derivatives test.

Best, Vladimir.
by Vladimir_Konjkov
Sun Dec 31, 2017 1:33 am
Forum: The CASINO program
Topic: parallel version breaks on multi determinant WFN
Replies: 4
Views: 14683

Re: parallel version breaks on multi determinant WFN

Dear Vladimir, Thanks for the report. Do you have an example that fails? (The MDET examples in CASINO/examples/TEST seem to work OK, at least with the gfortran and NAG compilers.) Best wishes, Neil. Hello Neil. My example is in the attachment. I'm still using the old version, it works completely. V...
by Vladimir_Konjkov
Fri Dec 29, 2017 7:23 pm
Forum: The CASINO program
Topic: parallel version breaks on multi determinant WFN
Replies: 4
Views: 14683

parallel version breaks on multi determinant WFN

Hello CASINO developers. I've found after upgrade to v2.13.673 from v2.13.639 that newest version fails when running with ANY multi determinant WFN in parallel mod with message: --Job's stderr-- [vladimir-Kubuntu-16:17932] *** An error occurred in MPI_Bcast [vladimir-Kubuntu-16:17932] *** reported b...
by Vladimir_Konjkov
Mon Dec 11, 2017 4:10 am
Forum: The CASINO program
Topic: backflow to the g-orbitals
Replies: 17
Views: 37928

Re: backflow to the g-orbitals

I think that unit tests for gaussian WFN gradients, second derivatives and laplacians are strongly required and it is desirable to follow the DRY principle.
by Vladimir_Konjkov
Tue Dec 05, 2017 6:21 pm
Forum: The CASINO program
Topic: backflow to the g-orbitals
Replies: 17
Views: 37928

Re: backflow to the g-orbitals

Hello Mike. It seems to me that all remaining analytic derivatives except first three are right. All first three are wrong similar way. Because g(4,0) = 3/8 * x^4 + 3/4 * x^2y^2 - 3 * x^2z^2 + 3/8 * y^4 - 3 * y^2z^2 + z^4 is symmetric upon x,y permutation, so dg(4,0)/dx + dg(4,0)/dy also should be b...