recover_pyscf does too much coercion to UHF

[lkwagner]

When symmetry is used, recover_pyscf changes it to UHF, presumably because of some incorrect logic. Here's an example that does it.

#! /usr/bin/env python
import numpy as np
from numpy import array
from pyscf import df, scf, dft
from pyscf import gto
import ase.io
import os

def ase_atoms_to_pyscf(ase_atoms):
                '''Convert ASE atoms to PySCF atom.

                Note: ASE atoms always use A.
                '''
#return [[ase_atoms.get_chemical_symbols(), ase_atoms.get_positions()] for i, atom in enumerate(ase_atoms)]
                return [ [ase_atoms.get_chemical_symbols()[i], ase_atoms.get_positions()[i]] for i in range(len(ase_atoms.get_positions()))]

def run_dft(xyzfile, directory):
    mol = gto.Mole()
    atoms = ase.io.read(xyzfile)
    mol.verbose  = 5
    mol.atom     = ase_atoms_to_pyscf(atoms)
    mol.basis    = 'ccecp-ccpvtz'
    mol.unit     = 'A'
    mol.ecp      = 'ccecp'
    mol.charge   = 0
    mol.spin     = 0
    mol.symmetry = True
    mol.output   = directory+'/mf.output'
    mol.build()

    mf = scf.KS(mol).density_fit()
    mf.max_cycle=200
    mf.chkfile = directory+'/mf.hdf5'
    #mf.level_shift=0.0
    mf.xc          = 'LDA_X,LDA_C_PZ'
    e_scf = mf.kernel()