It would be interesting to see whether additional backflow terms (including your omega) could improve the DMC energy more than in the paper DOI: https://doi.org/10.1103/PhysRevB.99.085121
Best wishes Vladimir.
Search found 187 matches
- Mon Nov 24, 2025 2:44 am
- Forum: The CASINO program
- Topic: Backflow term omega hinders optimization
- Replies: 2
- Views: 453
- Thu Nov 20, 2025 2:38 pm
- Forum: The CASINO program
- Topic: Backflow term omega hinders optimization
- Replies: 2
- Views: 453
Backflow term omega hinders optimization
The latest version in which the omega term was announced: ---[v2.13.1225]--- * Implemented three-electron backflow term omega -- Clio, 2025-11-19 It is an explicit three-electron correlation function in the same style as the eta term. cutoff lengths are separately optimisable and parameters are cons...
- Sat Sep 27, 2025 3:29 am
- Forum: The CASINO program
- Topic: Projection of a SJ WFN onto a CISD Basis via Stochastic Evaluation
- Replies: 1
- Views: 2321
Re: Projection of a SJ WFN onto a CISD Basis via Stochastic Evaluation
It's similar to electron-by-electron sampling. However, instead of changing coordinates, the column in the Slater matrix changes due to modifications in the single-electron orbitals. As in the paper, but without needing to compute the derivative.
https://pubs.acs.org/doi/10.1021/acs.jctc.7b00648
https://pubs.acs.org/doi/10.1021/acs.jctc.7b00648
- Fri Sep 26, 2025 8:44 am
- Forum: The CASINO program
- Topic: Projection of a SJ WFN onto a CISD Basis via Stochastic Evaluation
- Replies: 1
- Views: 2321
Projection of a SJ WFN onto a CISD Basis via Stochastic Evaluation
Hello CASINO developers. In quantum Monte Carlo (QMC) methods, the choice of trial wave function plays a crucial role in determining the accuracy and efficiency of energy estimates. A widely used ansatz is the Slater–Jastrow (SJ) wave function, defined as: ΨSJ (R)=J(R)⋅D0(R), where R denotes the co...
- Sat Sep 20, 2025 4:17 pm
- Forum: The CASINO program
- Topic: Bug report & feature request for adf2stowf.py utility
- Replies: 6
- Views: 96554
Re: Bug report & feature request for adf2stowf.py utility
ChatGPT told me that the code contains two methods for enforcing cusp conditions at nuclei: the Projection method (cusp_projection_matrix), which is commented out, and the Enforcing method (cusp_enforcing_matrix). Both methods always assume that orbitals are orthogonal (S = I), which is not generall...
- Sun Sep 14, 2025 12:52 am
- Forum: The CASINO program
- Topic: Bug report & feature request for adf2stowf.py utility
- Replies: 6
- Views: 96554
Re: Bug report & feature request for adf2stowf.py utility
I have created a Python package, https://pypi.org/project/adf2stowf/ , which includes a version from the CASINO distribution with minimal modifications (only adjusted to ensure proper package installation). This version will serve as the reference implementation. Unfortunately, in this version, the ...
- Fri Sep 12, 2025 1:07 am
- Forum: The CASINO program
- Topic: Bug report & feature request for adf2stowf.py utility
- Replies: 6
- Views: 96554
Re: Bug report & feature request for adf2stowf.py utility
ChatGPT told me that instead of scipy.weave, I could use pybind11 and rewrote part of the code as an... I've spent much of my life so far happily telling computers what to do. I do hope it's not going to be the other way round in the future. I called it Cognilator (noun) - A device or system design...
- Thu Sep 11, 2025 1:00 am
- Forum: The CASINO program
- Topic: Bug report & feature request for adf2stowf.py utility
- Replies: 6
- Views: 96554
Re: Bug report & feature request for adf2stowf.py utility
ChatGPT told me that instead of scipy.weave, I could use pybind11 and rewrote part of the code as an example https://github.com/Konjkov/adf2stowf/blob/main/stowfn.cpp, also fixed the calculation for the hydrogen atom and added comments... I think it will also help with the virtual orbitals. Fashion ...
- Wed Sep 10, 2025 9:59 am
- Forum: The CASINO program
- Topic: Bug report & feature request for adf2stowf.py utility
- Replies: 6
- Views: 96554
Bug report & feature request for adf2stowf.py utility
Hello CASINO developers, The adf2stowf.py utility included in the CASINO distribution is not working. This is due to the fact that the scipy.weave module is outdated and no longer supported in recent versions of SciPy, along with several other minor issues. I have created a project at https://github...
- Sat Aug 30, 2025 3:03 am
- Forum: Quantum Monte Carlo
- Topic: Backflow transformation for Gaussian orbitals
- Replies: 3
- Views: 65399
Re: Backflow transformation for Gaussian orbitals
and the equation
has a stationary point at which the optimization of ξi will converge and this is obvious flattened (corrected) trial function.