"""Test suit for the CP2K ASE calulator.

http://www.cp2k.org
Author: Ole Schuett <ole.schuett@mat.ethz.ch>
"""

from ase.build import molecule

inp = """
&FORCE_EVAL
   METHOD Quickstep
   &DFT
      BASIS_SET_FILE_NAME BASIS_MOLOPT
      &MGRID
         CUTOFF 400
      &END MGRID
      &XC
         &XC_FUNCTIONAL LDA
         &END XC_FUNCTIONAL
      &END XC
      &POISSON
         PERIODIC NONE
         PSOLVER  MT
      &END POISSON
   &END DFT
     &SUBSYS
      &KIND H
         BASIS_SET DZVP-MOLOPT-SR-GTH
         POTENTIAL GTH-LDA
      &END KIND
   &END SUBSYS
&END FORCE_EVAL
"""


def test_h2_none(cp2k_factory):
    # Basically, the entire CP2K input is passed in explicitly.
    # Disable ASE's input generation by setting everything to None.
    # ASE should only add the CELL and the COORD section.
    calc = cp2k_factory.calc(
        basis_set=None,
        basis_set_file=None,
        max_scf=None,
        cutoff=None,
        force_eval_method=None,
        potential_file=None,
        poisson_solver=None,
        pseudo_potential=None,
        stress_tensor=False,
        xc=None,
        label='test_H2_inp',
        inp=inp
    )
    h2 = molecule('H2', calculator=calc)
    h2.center(vacuum=2.0)
    energy = h2.get_potential_energy()
    energy_ref = -30.6989595886
    diff = abs((energy - energy_ref) / energy_ref)
    assert diff < 1e-10