A fourth-order many-body perturbation theory calculation of the first and second electric dipole hyperpolarizability of ammonia

Abstract

The electric dipole moment (μ α), dipole polarizability (α α,β) and second (γ αβγδ) dipole hyperpolarizability of ammonia were obtained from finite-field self-consistent-field (SCF) and complete fourth-order many-body perturbation theory (MP4) calculations. With z as the C 3 axis, the following SDQ-MP4 results are reported: μ z = −0.6034 e a 0, α = 14.01 and Δα = 1.59 e 2 a 2 0 E −1 h, β = 30.47 and Δβ = 8.87 e 3 a 3 0 E −2 h, γ = 3864 e 4 a 4 0 E −3 h. The triplets (T4) contribution to the fourth-order correction for the above properties is estimated to be 0.0083 e a 0, 0.29 and 0.25 e 2 a 2 0 E −1 h, 4.42 and 5.43 e 3 a 3 0 E −2 h, 311 e 4 a 4 0 E −3 h, respectively.