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Dear Ichibha! In this case, I would guess that you simply need more steps. Your total (imaginary) propagation time is only 26 a.u. I always use an estimate of about 1 a.u. in correlation time. So you are not converged in reblocking yet. So what you see is that you have not reached a plateau yet. The...

I would sort of not trust either. Yours not because the error in the variance at your "peak" is nearly as large as the variance and the authomatic reblocking one not because it is not a a plateau. Overall, this looks a bit strange to me. Is this a VMC or a DMC run? What kind of system is t...

Dear Neil, the time-step and equilibration times you suggest, seem to be similar to what Fan-Wang used (and he says he checked for the equilibration time). This would leave the population bias as source of error (although I am still not convinced that a linear extrapolation from 0.002 and 0.0006 for...

Dear Fan-Wang, The point is one also needs to optimize Jastrow factor carefully even in all-electron calculations if such difference always exists. no, if the DMC energy of an all-electron calculation depends on the Jastrow, then something is going seriously wrong and you should investigate what it ...

Are these all electron calculations? (Looks like it, since it seems that the time step has to be very small) For me it looks as if the time step error were still considerable without a Jastrow (not surprisingly since the time-step error will be smaller for a better trial wavefunction). I would not b...

But a very informative one
Thanks!

Hi Neil! I understand that reweighted and unreweighted variance are not the same and I would understand if the variance and energy would go up in varmin_linjas (which, if I am not mistaken, is based on the unreweighted varaiance) after having done a varmin on the reweighted varmin. But in the varmin...

Hi Neil! Thank you for your answer! Although it does not help of course, I am quite glad you say that short answer is "I don't know"... A global minimum in variance cannot explain my observation since you can see the variance also going up in the example above. As to the fixnl: I did set i...

Hi! I do have the cutoffs optimized in varmin and I do not change the flag for the varmin_linjas, but the flag is automatically ignored in varmin_linjas. So yes, if I were to run varmin_linjas alone, I would expect a higher energy, since the cutoffs are not optimized. However, that is not what I do:...

I am running an optimization on a system with PPs. I started with a small varmin calculation (a couple of thousand configs). Then I added a varmin_linjas calculation using more configs. Interestingly, I see the following: VMC #1: E = -1295.332(6) ; var = 29.14(8) (correlation.out.0) VMC #2: E = -129...