Too low Energy

[davidsousarj]

Hi,

I noticed that, in the provided example, the calculated energy is lower than the Full CI energy, which is not possible.

Running the example file (hydrogen fluoride), I get converged SCF energy = -99.9593211672815 and Selected CI E = [-104.43139484], and if I add the following lines to the script:

from pyscf import fci
myfci = fci.FCI(myhf)
fci_e, fci_ci = myfci.kernel()
print(fci_e)

the FCI energy is -100.10211465665482.