Basis functions triatomic molecules

Floquet theory principles, 35—36 single-surface nuclear dynamics, vibronic multiplet ordering, 24—25 Barrow, Dixon, and Duxbury (BDD) method, Renner-Teller effect tetraatomic molecules, Hamiltonian equations, 626-628 triatomic molecules, 618-621 Basis functions ... 

In Section 2.1 we derived the expression for the transition rate kfi (2.22) by expanding the time-dependent wavefunction P(t) in terms of orthogonal and complete stationary wavefunctions Fa [see Equation (2.9)]. For bound-free transitions we proceed in the same way with the exception that the expansion functions for the nuclear part of the total wavefunction are continuum rather than bound-state wavefunctions. The definition and construction of the continuum basis belongs to the field of scattering theory (Wu and Ohmura 1962 Taylor 1972). In the following we present a short summary specialized to the linear triatomic molecule. 

Let us consider for example a triatomic molecule. By using Jacobi coordinates ri,r2, and 0, and Legendre basis functions 1(9)>, the angular-electronic matrix elements of the Hamiltonian are equal to [2]... 

In the following, we discuss the basis set convergence characteristics of the harmonic frequencies and anharmonic corrections computed with CCSD(T) wave functions for several strongly bound diatomics as well as the triatomic hydrogen cyanide molecule (HCN). 

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