The CASINO forum

If you do this (scaling down the number of stats accumulation steps for each independent calculation rather than scaling down the target population for each independent calculation) then you will spend nearly all your time equilibrating walkers.

Best wishes,

Neil.

The other obvious point is that if you just want a series of independent DMC calculations, you can just submit independent jobs with timer-derived random seeds and average the results at the end. If you want to be more careful about non-duplication of random seeds, there is a script called set_rando...

I think your suggestion is, basically, to perform k independent DMC simulations with n configurations each and m/k steps. At one point this was enabled in CASINO (with 1<=k<=P , where P is the number of MPI processes). See the dmc_npops keyword back in CASINO's Git history. One major con of this app...

Does the trick of looking at a N"P" (nitrogen "phosphide") molecule, where the nitrogen is all-electron and the phosphorus is actually a pseudonitrogen atom not work?

Best wishes,

Neil.

CASINO allows you to have both all-electron and pseudopotential ions present. For an example, see CASINO/examples/molecule/silane/ground_state which has a silicon pseudopotential, while the hydrogen atoms are all-electron. Before 2014 there used to be a mishmash of CASINO keywords related to allowin...

Perhaps you could look at a "nitrogen phosphide" molecule, where the nitrogen is all electron (no n_pp.data file is supplied) and the phosphorus pseudopotential in p_pp.data is actually just a renamed nitrogen pseudopotential? To create this p_pp.data file you could just rename n_pp.data a...

Dear Vladimir, Is your point that, for example, VMC variance isn't a perfect measure for comparing two different types of wave function when they are optimised by minimising the variance? Or is your point that we optimise wave functions by some criterion that stands in for the one we are ultimately ...

Sorry it has taken me ages to reply. Analytical derivatives w.r.t. backflow parameters will certainly get messy. Obviously I agree that you can evaluate linearly constrained derivatives for parameters by evaluating unconstrained derivatives and using linear algebra. This could be done using the proj...

An alternative approach for dealing with the homogeneous linear constraints would be to use SVD to find the basis spanning the nullity (the solution space) and then the parameters in correlation.data would be the coefficients of those basis vectors, again giving an independent set of parameters. It'...

For the "old" Jastrow factor in pjastrow.f90, the subroutine "get_linear_basis" returns analytical derivatives w.r.t. the independent subset of linear parameters. At present this is only used in the "varmin-linjas" optimisation method, however. Numerical differentiation...