The CASINO forum

I discovered that local pseudopotentials without core electrons have been developed for H-Be, they also contain only local channel. (https://pubs.aip.org/aip/jcp/article/151/14/144110/75444/A-new-generation-of-effective-core-potentials-from). They are available on the website https://pseudopotential...

I tried converting the pseudopotential as described above. Using: B Small Core DF AREP (Trail & Needs) 5.0 3.0 3 8 8 8 Vs - Vd 6.08975909 24273.45582357 0 6.22754424 -24267.33981731 0 7.95360685 1449.36679089 1 5.26256053 -22823.91537604 1 5.07697261 21374.54858515 1 14.04620763 -256.36140271 2 ...

Hello Neil. I created a repository to illustrate my algorithm https://github.com/Konjkov/pycasino You can install it with the command (under Linux to virtualenv) pip install . from project root directiry. You can execute the test task by running any path from the file https://github.com/Konjkov/pyca...

I have already written all the code, now testing and any cutoffs are still outside of my algorithm. Not sure if they need to be optimized at all. Unfortunately third partial derivatives of the wave function w.r.t the electron coordinates are necessary. I hardly read the CASINO code except for two pr...

The main problem in calculating the analytical energy gradient w.r.t backflow parameters is that in equation of Ti we have laplacian of backflowed slater determinant as Screenshot_20230311_115913.png additional differentiation this laplacian w.r.t. backflow parameters requires the calculation of 3-r...

I tried to explain above that my idea is different but independent set of parameters is the same as yours. As we calculate the gradient in the space of all parameters, we know how to project gradient to nullspace of ∇g (from above), let me remind you that g(p) = c - parameters constraints. At the po...

We need the linear dependence of the parameters to be preserved in the vicinity of the point at which we calculate the partial derivatives w.r.t parameters. Therefore we need jacobian matrix like this. Screenshot_20230308_201830.png Constrained partial derivatives is nullspace of ∇g which may be fun...

Hello Neil. I wanted to talk about the partial derivatives of the wave function and local energy with respect to the Jastrow and Backflow parameters, that are needed for optimization. These partial derivatives could be easily obtained analiticaly if the parameters were not linearly dependent. I noti...

The forum works terribly, my authorization session is constantly interrupted. It is not possible to write a long message. This would be more intuitive if the comments reflected the order of the terms.

I'm sorry Neil it's absolutely impossible to write

Hellow QMC folks. As described in "Optimization of quantum Monte Carlo wave functions by energy minimization" of Julien Toulouse. "The most straightforward way to energy-optimize linear parameters in wave functions is to diagonalize the Hamiltonian in the variational space that they d...