GKS calculations for PBE and BP86 differs for XCFun and Libxc

Dear dev Dear PySCF developers,

I calculate Li atom, using both Libxc and XCFun, the Exc differs. And the same problem occurs, when using BP86, but not for BLYP.

`molu = gto.Mole() molu.verbose = 6 molu.atom = “Li 0 0 0” ### molu.spin=1 # ^ Spin molu.basis = “sto-3g” # ^ Basis molu.max_memory = 5000 molu.build()

mftot_nr = dft.GKS(molu) mftot_nr.xc = “BP86” # ^ functional mftot_nr.max_cycle = 0 # ^ max cycle mftot_nr.kernel() `

Now, I can’t understand why this could happen, thanks a lot!

[Haskiy]

I met the similar question. And I try my best to solve it , however, I failed.

[hoshishin]

Thank you, sunqm! Use dft.libxc.eval_xc and dft.xcfun.eval_xc for a single grid can truly see the difference between those 2 implementation.