Backflow term omega hinders optimization
Posted: Thu Nov 20, 2025 2:38 pm
The latest version in which the omega term was announced:
For exampe:
CASINO/examples/TEST/Input/neon_atom/varmin_bfonly
returns varmin_bfonly.tgz
Also, the format of the section is incorrect in the documentation: Spin dep accepts only two values: 1--2.
Best wishes Vladimir.
returns an error when optimizing the test input.---[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
considered equal between any two particles in a triplet that share a spin
pair.
For exampe:
CASINO/examples/TEST/Input/neon_atom/varmin_bfonly
returns varmin_bfonly.tgz
Also, the format of the section is incorrect in the documentation: Spin dep accepts only two values: 1--2.
Code: Select all
START OMEGA TERM
Expansion order
2
Spin dep (0->uu=dd=ud; 1->uu=dd/=ud; 2->uu/=dd/=ud)
1
Cut-off radius ;
Optimizable (0=NO; 1=YES)
0.d0
0
Parameter ;
Optimizable (0=NO; 1=YES)
END OMEGA TERMBest wishes Vladimir.