The electronic structures of titanium compounds, TiFe, TiCo and TiNi with C
sCl-type structure are investigated by the DV-X alpha molecular orbital met
hod. From the results of the calculation, it is found that hydrogen interac
ts more strongly with constituent elements, X (=Fe, Co, Ni), rather than Ti
atoms. The bond strength between Ti and X atoms changes in the sequence, F
e>Co>Ni. This is the same order as the capacity of the hydrogen absorption
in these TiX compounds. The characteristics of the hydrogen absorption in t
hese compounds are discussed in view of the nature of the chemical bond bet
ween atoms. (C) 1999 Elsevier Science S.A. All rights reserved.