Search found 166 matches
- Wed Nov 01, 2023 12:21 pm
- Forum: The CASINO program
- Topic: Problem with pseudopotential transformation
- Replies: 4
- Views: 25123
Re: Problem with pseudopotential transformation
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 ...
- Fri Mar 17, 2023 7:03 am
- Forum: Quantum Monte Carlo
- Topic: Constrained derivatives.
- Replies: 9
- Views: 57982
Re: Constrained derivatives.
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...
- Sat Mar 11, 2023 5:05 am
- Forum: Quantum Monte Carlo
- Topic: Constrained derivatives.
- Replies: 9
- Views: 57982
Re: Constrained derivatives.
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...
- Thu Mar 09, 2023 4:30 pm
- Forum: Quantum Monte Carlo
- Topic: Constrained derivatives.
- Replies: 9
- Views: 57982
Re: Constrained derivatives.
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...
- Wed Mar 08, 2023 1:44 pm
- Forum: Quantum Monte Carlo
- Topic: Constrained derivatives.
- Replies: 9
- Views: 57982
Re: Constrained derivatives.
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...
- Wed Mar 08, 2023 4:55 am
- Forum: Quantum Monte Carlo
- Topic: Constrained derivatives.
- Replies: 9
- Views: 57982
Re: Constrained derivatives.
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...
- Tue Mar 07, 2023 9:57 am
- Forum: The CASINO program
- Topic: Order for spin-pairs in electron systems
- Replies: 3
- Views: 62036
Re: Order for spin-pairs in electron systems
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
I'm sorry Neil it's absolutely impossible to write
- Tue Mar 07, 2023 8:34 am
- Forum: Quantum Monte Carlo
- Topic: Constrained derivatives.
- Replies: 9
- Views: 57982
Constrained derivatives.
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...
- Tue Mar 07, 2023 7:56 am
- Forum: The CASINO program
- Topic: Order for spin-pairs in electron systems
- Replies: 3
- Views: 62036
Order for spin-pairs in electron systems
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 ...
- Sun Sep 25, 2022 12:34 pm
- Forum: Quantum Monte Carlo
- Topic: Backtranformed Jastrow
- Replies: 1
- Views: 12495
Backtranformed Jastrow
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...