TOPOLOGICAL COMPLEXITY OF POTENTIAL SURFACES AND APPLICATION TO C2H2 MOLECULE

In this work, we search for the ''simplest'' complete surfaces of systems with three and four atoms, i.e. the minimal sets of critical points with their index, which are topologically consistent in the whole configuration space. Then we show the smallest change in the A2B2 system by requiring at least one stable ''acetylene'' configuration and one stable ''vinylidene'' configuration, like on the C2H2 surface. Finally, we give complete sets of minima, saddle points and maxima obtained for C2H2 with analytical potentials proposed in the literature and with a semiempirical method at the CAS-CI level.