The CASINO forum

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...

Hello, dear Casino developers. Recently I was discouraged by the strange fact that I always thought that in the file correlation.data the lines like Spin dep (0->uu=dd=ud; 1->uu=dd/=ud; 2->uu/=dd/=ud) determines the order of coefficients in all Jastro and backflow terms. However, looking closer (in ...

Hello everybody. VMC is just Multiple integral brevity, written in bra–ket notation <φ(r)|H|φ(r)>/<φ(r)φ(r)> then backflow tranformation (if it includes Jastrow factor) is change of variables and only requires the calculation of the determinant of backflow tranformation Jacobian matrix opposed to wh...

Hello Neil

I also use this script because I took your CASINO source code with comments and partially rewrote it to python3 + numpy + numba
and although it works 3-7 times slower than on Fortran, it is enough to compare results and testing.

Best Vladimir

Greetings to all who use the Casino. I found an issue in the molden2qmc script that shows up in Python version 3.10. Corrections in the next PR - https://github.com/Konjkov/molden2qmc/c ... 0778cd177d
Sincerely, Vladimir

Dear Pablo and Neil. Thanks for the answers, I just wanted to quote the article of Dario Bressanini "Implications of the two nodal domains conjecture for ground state fermionic wave functions" which stated that the quality of the HF wave function for four electron atoms can be greatly impr...