Study on electronegativity and hardness of the elements by density functional theory

Ionization Potentials and electron affinities of 103 elements are calculated by density functional theory at local density approximation (LDA) level and the LDA/AN level with further non-local corrections for exchange and correlation included self-consistently. The finite-difference method is used in calculations on electronegativity and hardness of 103 elements, The calculated results for the various quantities represent an improvement over previous calculations by Robles and Bartolotti under a spin polarized density function theory with the X-GL and X-alpha approximations to the exchange-correlation function. The present calculation is to examine both the LDA and LDA/NL approximations in calculations for the ionization potential and electron affinity of the elements with an improved slater transition-state method, and relativistic effects have also been taken into account in the present paper for 103 elements as compared with 86 in the previous work. It is shown that the results calculated by LDA/NL and the improved slater transition-state method in general agree well with experimental values presented by Pearson, and are better than the reported values in the literatures([11,12]).