Why the Kirkwood-Pople-Schofield method works so well

Applied quantum chemistry

“…The polarizabilities can then be expressed in terms of moments of the electron density calculated over the unperturbed wave function. Although in principle this procedure is justified only for exact wave functions, quite good results are obtained even at the SCF Hartree-Fock level due to a fortunate cancellation of errors [1213].…”

An extended KPS method for calculating multipole polarizabilities – application to crystalline ions

“…Many reliable methods of calculating the dipole polarizabilities of atoms and ions are now available and a fairly clear picture of how α varies with atomic number and ionization state has emerged. The KirkwoodPople-Schofield (KPS) approach is one such technique, a simple variational method capable of giving good values of α. Fraga and co-workers [8,9] have used the method to calculate polarizabilities for all elements and the reasons for the success of their simple procedure have been discussed by Sadlej [10]. We have used the method [11,12] to calculate polarizabilities of atoms and ions containing core holes, and to investigate the dipole polarizabilities of O 2-and S 2-ions at the (001) surfaces of oxides and sulfides of rocksalt structure.…”

The variation of multipole polarizability at the surface of alkaline earth oxides and sulfides

“…Many reliable methods of calculating the dipole polarizabilities of atoms and ions are now available and a fairly clear picture of how α varies with atomic number and ionization state has emerged. The KirkwoodPople-Schofield (KPS) approach is one such technique, a simple variational method capable of giving good values of α. Fraga and co-workers [8,9] have used the method to calculate polarizabilities for all elements and the reasons for the success of their simple procedure have been discussed by Sadlej [10]. We have used the method [11][12][13] to calculate polarizabilities of free atoms and ions, atoms and ions containing core holes, and for ions in crystal.…”