Order for spin-pairs in electron systems
Posted: Tue Mar 07, 2023 7:56 am
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 correlation.out.0 for blank terms), I discovered, and even found in the documentation (page 69, 11-link),
that the order for the u-term is different, namely (0->uu=dd=ud; 1->uu=dd/=ud; 2->uu/=ud/=dd), and in my code, apparently by mistake,
I implemented just such order for all other terms (f-, eta-, phi-, theta-). I would like to know what is the actual order.
Having carried out the calculation for the helium atom (which only has antiparallel pairs), I can assume that it is just such (uu/ud/dd).
Best Vladimir.
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 correlation.out.0 for blank terms), I discovered, and even found in the documentation (page 69, 11-link),
that the order for the u-term is different, namely (0->uu=dd=ud; 1->uu=dd/=ud; 2->uu/=ud/=dd), and in my code, apparently by mistake,
I implemented just such order for all other terms (f-, eta-, phi-, theta-). I would like to know what is the actual order.
Having carried out the calculation for the helium atom (which only has antiparallel pairs), I can assume that it is just such (uu/ud/dd).
Best Vladimir.