1. The nonsinglet instabilities of the hartree-fock solutions for nonalternant hydrocarbons

   • Azumao Toyota
   • Takeshi Nakajima

   Original Investigations Pages: 297 - 308

2. Additivity model calculations of UHF spin densities and charge densities in methyl-substituted radical cations

   • Krishan K. Sharma
   • Russell J. Boyd

   Original Investigations Pages: 309 - 317

3. Eigenvalues of graphs with threefold symmetry

   • Susan S. D'Amato

   Original Investigations Pages: 319 - 326

4. Calculation of harmonic force constants, vibrational frequencies and integrated intensities of some organic molecules using the MINDO—Forces method

   • Abdul -Latif K. Al-Jiburi
   • Kisma H. Al-Niami
   • Muthana Shanshal

   Original Investigations Pages: 327 - 335

5. Structure and charge distribution of some alkynoyl cations

   • Otilia Mó
   • Manuel Yáñez

   Original Investigations Pages: 337 - 343

6. Application of the direct configuration interaction method to the ground state of O₂

   • Ian Ferguson
   • Nicholas C. Handy

   Original Investigations Pages: 345 - 353

7. Chemical graphs

   • Alexandru T. Balaban

   Original Investigations Pages: 355 - 375

8. Relative stability of the² A _1g and² E _g states of the C₂H ₆ ⁺ ion

   • Federico Moscardó
   • Miguel Paniagua
   • Emilio San-Fabián

   Short Communication Pages: 377 - 381

9. Book reviews

   • Karlheinz Schwarz

   BookReview Pages: 383 - 383

10. Book reviews

    • J. Troe

    BookReview Pages: 384 - 384