The CASINO forum

Hi Vladimir, Li-atom in cc-pVDZ basis, WFN consists of 1 geminal orbitals and an orbital filled with an unpaired electron Unpaired electrons are indeed not supported; the geminals are supposed to be determinants of square matrices of size Nup x Ndown which must therefore satisfy Nup = Ndown. If you...

Patch now available in current beta. Best, Pablo Hello Pablo, thanks for the opportunity to test the calculations with geminals ansatz. I chose the simplest systems and performed the calculations in the qchem program. 1. Li-atom in cc-pVDZ basis, WFN consists of 1 geminal orbitals and an orbital fi...

Hi Vladimir How could I update the number of "orbitals allowed" in the input file? Ok, this is a bug. The MAGP wave function in CASINO has only been used with electron gas orbitals, and for Gaussian orbitals the basis is mistakenly trimmed to the number of electrons (as one would do for a...

Hello Pablo, Fan I've tried to start geminal WFN calculation for Be atom involving 2p orbitals in geminal construction. As input I want to use geminals in form described in https://aip.scitation.org/doi/10.1063/1.1503773 I use cc-pVDZ basis which has 14 orbitals for Be atom. GEMINAL: Geminal 1: Para...

Hello Alan Could you please provide your VMC energies for benzene to compare with those presented in the https://www.ncbi.nlm.nih.gov/pubmed/25725716 (TABLE VII) Despite the fact that in this work totally symmetric Jastrow factor with respect to electron permutations was proposed, VMC energies for H...

Hello Philip Formats for ECP used by different programs are similar. On the https://bse.pnl.gov/bse/portal you can get the desired potential in various formats but not in Casino. And I do not know how to convert to, but maybe some clues can be found in the directory CASINO/utils/pseudo_converters of...

Hello Philip For calculations with pseudopotential (ECP) is usually required to have two formats for the pseudopotential (ECP) — one for conventional quantum chemical programs, the other for CASINO. It is also necessary to have a basis corresponding to this pseudopotential (ECP). On the page https:/...

Hello CASINO developers I am faced with CASINO behavior that confused me much. The wavefunction of a given CASSCF state is written as a sum of a configuration state functions CSF (for example linear combination of Slater determinants) each adapted to a total spin S. Each CSF is constructed from a co...

I am performing a vmc_opt calculation on benzene in which I set uu/=dd/=ud in U and F and u/=d in Chi. This appears to give a considerably better energy than uu=dd and u=d. I am concerned that since this is analogous to a spin unrestricted wavefunction, there might be spin contamination present. Is...

Hello all. I noticed that when one optimize backflow parameters using VMC emin, the AE CUTOFFS parameters is bad or not optimized at all i.e. accepts random values or not optimal in terms of subsequent DMC calculation. As stated in APPENDIX B: ZEROING THE BACKFLOW DISPLACEMENT AT AE ATOMS in article...