  The present study explores electronic and structural properties, ionization
potential (IP), electron affinity (EA), polarizability ({\alpha}), chemical
potential (\mu), hardness ({\eta}), softness (S), band gap
({\Delta}E(HOMO-LUMO)) and spectral characteristics of beryllium hydride
oligomers by quantum chemical treatment. The discrepancies in the calculated
reactive descriptors of molecules are presumably due to variations in electron
distribution and spin pairing near Fermi level. The molecules BeH2, Be3H5,
Be5H10, Be7H14 and Be9H18 have been found to be more stable than Be2H4, Be4H8,
Be6H12, Be8H16 and Be10H20. Ultra-soft pseudopotentials for electron-nuclei
interactions with local density approximation (LDA) and generalized gradient
approximation (GGA) have been used to understand the nature of bonding in
crystalline beryllium hydride. The observed band gap value of crystalline BeH2
is comparable with the band gap value of beryllium hydride oligomers
