ELECTRONIC-STRUCTURE AND VIBRATIONAL-SPECTRUM OF SEMICARBAZIDE

SCF MO LCAO has been used in the MNDO/H approximation in quantum-chemi cal optimization of the geometrical parameters for the cis and trans i somers of semicarbazide H2NCONHNH2. Estimates have been made on the ef fective atomic charges, bond orders, enthalpy of formation, ionization potential, and dipole moment. The vibrational problem has been solved for the trans isomer and the deuterated analog. Force constants and v ibrational frequencies have been calculated. A theoretical basis is gi ven for assigning the frequencies to vibrations of groups on the basis of the normal modes and the potential-energy distribution.