ionisation energy

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ionisation energy

A term defined in the context of mass spectrometry as the minimum energy needed to remove an electron from an atom or molecule to produce a positive ion.
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Table 1: Thermodynamic energies in kJ/mol: bond dissociation energies, ionization potential, proton dissociation energies, proton affinities, and electron transfer energies in gas phase and in water at B3LYP/6-31+G(d,p) level.
Of course, historically, the Koopmans theorem was developed within Hartree-Fock theory giving the route to predict ionization potentials [41], while giving simple physical interpretation to the eigen value of the Fock matrix and justifying the existence of the "orbitals" by their observable energies [42, 43].
Four water molecules Cellobiose Heat of formation -260.88 -491.31 (kcal x [mol.sup.-1]) Electron energy (eV) -3903.2 -35114.2 Core-core repulsion (eV) 25079 30066.9 Total energy (eV) -1395.3 -5047.3 Ionization potential (eV) 12.2 10.8 Molecular weight (D) 72.061 326.30 Cellobiose + 4 water molecules Heat of formation -753.73 (kcal x [mol.sup.-1]) Electron energy (eV) -50193.8 Core-core repulsion (eV) 43751.1 Total energy (eV) -6442.6 Ionization potential (eV) 10.3 Molecular weight (D) 398.361 TABLE 2: Heat of formation and electronic properties of cellobiose unit and water molecule.
The ionization potential (Ip) [14] of free donor in methanol medium was determined using the equation Ip = 5.76 + 1.53 x 10-4 CT.
He also relied on thermal equilibrium and the ionization potentials of the elements.
For the positive ion clusters, similar energies called vertical ionization potentials are calculated.
Ionization potential (IP) and proton dissociation enthalpy (PDE) represent enthalpies of the SETPT process [7].
There were plenty of quantum mechanical calculations and determinations of ionization potentials and studies of trends in electronegativity to keep me burning the midnight oil.
The section on charge distributions looks at such topics as core and valence electrons, the valence region of molecules, and charges and ionization potentials. Turning next to the energy calculation of chemical bonds, he covers thermochemical formulas, chemical bond theory, and bond dissociation energies.
Because all species have lower ionization potentials than helium, the HID is a universal detector.