Vibrational effects on electric properties of cyclopropenone and cyclopropenethione

Abstract

Vibrational contributions to the dipole polarizabilities and hyperpolarizabilities of cyclopropenone and cyclopropenethione are reported. Simultaneous calculations have been carried out for the respective saturated and noncyclic counterparts of these molecules. The results have been analyzed and interpreted in terms of different structural and electronic features of the studied molecules: i.e., the oxygen–sulfur replacement, the saturation of the carbon ring, and the removal of the intramolecular strain. For static dipole polarizabilities the vibrational contribution computed at the molecular equilibrium geometry can account for more than 10% of the total value for a given component of the tensor. Both the zero-point vibrational average and pure vibrational terms are important for most of the studied molecules. In the case of the first dipole hyperpolarizability the total vibrational correction is dominated by the pure vibrational term. The vibrational corrections to dipole polarizabilities show certain regularities which can be interpreted in terms of the electronic structure of the investigated molecules. Much less clear is the pattern of behavior for the first dipole hyperpolarizability. It has been found, however, that the analysis of these data is greatly facilitated by the separate consideration of the nuclear relaxation and curvature terms. Limited study of the frequency dependence of the calculated vibrational corrections shows that in the case of the dipole polarizability, they are almost quenched to zero. In contrast, at nonzero frequencies, the vibrational contribution to the first dipole hyperpolarizability tensor β(−ω;ω,0), which determines the so-called electro-optic Pockels effect, can be as important as the pure electronic term.

Density-Functional-Based Determination of Vibrational Polarizabilities in Molecules within the Double-Harmonic Approximation: Derivation and Application

“…As discussed in Ref. 35 the water dimer represents an extreme example of this case. As shown in Table I, we find the electronic polarizability of this molecule (3.19Å 3 ) to be approximately twice that of a water monomer.…”

Vibrational corrections to electric properties of relativistic molecules: The coinage metal hydrides

“…This alternative partition of vibrational contributions resulting from BKPT has been found to offer interesting possibilities in terms of the interpretation of the vibrational effect on molecular properties, 36 and will be explored in this paper. Let us note that partitions Eqs.…”

“…This is supported by the observation that for relatively weak bonds the nuclear relaxation contribution is the domi-nant term in the total vibrational correction to dipole polarizabilities. 36 …”

Initial convergence of the perturbation series expansion for vibrational nonlinear optical properties

“…In fact, in many cases vibrational hyperpolarizability contributions are as large as, or larger than, their electronic counterparts. [1][2][3][4][5][6][7] A general sum over states ͑SOS͒ perturbation treatment of vibrational hyperpolarizabilities at nonresonant frequencies has been developed by Bishop and Kirtman ͑BK͒. [8][9][10][11] In their treatment the pure vibrational component ͑as distinct from the vibrational averaging contribution͒ is identified as the set of terms involving one or more intermediate states associated with nuclear motion on the ground electronic state potential-energy surface.…”