Potential energy surfaces for the collinear H-3(+) system

Approximate potential energy surfaces for the two lowest singlet states of collinear H-3(+) are computed using the diatomics-in-molecules (DIM) approa ch. permanent dipole moments for these states and transition dipole moments between them are computed analytically in this approximation. These potent ial surfaces and dipole functions are essential for a realistic description of the interaction between the H-3(+) and a strong external optical field. The computed results show the correct asymptotic behavior as the inter-nuc lear distances in H-3(+) become large and are in good agreement with an acc urate ab initio calculation but are not currently available as a complete p ackage, either in the literature or from existing sb initio quantum-chemist ry softwares. (C) 2000 Elsevier Science B.V. All rights reserved.