TABLE II.

Mapping relations for calculation of spectroscopic observables. For HOD, E is the electric field (in atomic units) at the D atom and along the O-D bond; for urea, E_C is the electric field at the C atom and along the C=O bond, and E_Ni is the electric field on N atom i and in the C=O bond direction. ω₁₀ and ω₂₁ are the vibrational frequencies in cm⁻¹, µ′ is the dipole derivative (in atomic units), and x₁₀ and x₂₁ are the position matrix elements (in atomic units).

SPC/E water OD stretch

ω10 = 2762.6 – 3640.8E – 56641E2

ω21 = 2695.8 – 3785. 1E – 73074E2

µ′ = 0.1333 + 14.17E

x10 = 0.16627 – 2.0884×10−5ω10

x21 = 0.23228 – 2.8822×10−5ω21

Urea CO stretch

ω10 = 1714 + 2154EC + 3071(EN1 + EN2)