PT2 with quantum nucleus
This is a minimal input for a second order propagator theory (Propagathor Theory, PT) calculation to obtain the electronic ionization energies and proton binding energies for a water molecule. The PT2 corrections are computed when “propagatorTheoryCorrection=2” is added to the input:
GEOMETRY
e-(O) 6-31G 0.0000 0.0000 0.1173
e-(H) 6-31G 0.0000 0.7572 -0.4692
e-(H) 6-31G 0.0000 -0.7572 -0.4692
O dirac 0.0000 0.0000 0.1173
H-a_1 Nakai-7-SPD 0.0000 0.7572 -0.4692
H-b_1 Nakai-7-SPD 0.0000 -0.7572 -0.4692
END GEOMETRY
TASKS
method = "RHF"
propagatorTheoryCorrection=2
END TASKS
The PT2 output will include a summary of the Koopmans’ (KT) and self-energy corrected (EP2) results for the highest occupied and lowest unoccupied orbital of each species,
POST HARTREE-FOCK CALCULATION
PROPAGATOR THEORY:
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PROPAGATOR FORMALISM FOR SEVERAL FERMIONS SPECIES
ORDER OF CORRECTION = 2
The following articles must be cited:
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J. Chem. Phys. 137, 074105 (2012)
J. Chem. Phys. 138, 194108 (2013)
CPL coming soon
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SPECIES: E-
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Orbital KT (eV) EP2 (eV) P.S
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5 -13.335244 -10.140654 0.853889
6 5.362715 4.925340 0.952097
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SPECIES: H-A_1
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Orbital KT (eV) EP2 (eV) P.S
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1 -24.603421 -17.007032 0.877287
2 -23.948321 -57.734065 0.538455
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SPECIES: H-B_1
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Orbital KT (eV) EP2 (eV) P.S
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1 -24.603421 -17.007032 0.877287
2 -23.948321 -57.734065 0.538455
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For the occupied orbitals, KT and EP2 results are estimates of the energy requiered to remove a particle from the corresponding orbital (ionization potential). For the unoccupied ones, KT and EP2 results are estimates of the energy gained by adding a particle to the orbital (electron affinity). Here, the Pole Strength (P.S) serves as a quantity that validates the diagonal (pseudoparticle) approximation employed. A P.S value below 0.85 usually indicates that the diagonal approximation is not reliable.