[1] Á. Somogyi, Z. Dinya, A. Császár, and P. Császár, Use of Semiempirical Methods for the Prediction of Equilibrium Geometries and Ionization Potentials of 4H-Pyran-4-one and Sulphur Analogues, J. Mol. Struct. (THEOCHEM), 1985, 133, 95-104. https://doi.org/10.1016/0166-1280(85)85009-0 [PDF(605 kB)]