Second Harmonic Generation, Electrooptical Pockels Effect, and Static First-Order Hyperpolarizabilities of 2,2′-Bithiophene Conformers: An HF, MP2, and DFT Theoretical Investigation

Table 2

Dipole moments (D), static electronic polarizabilities (a.u.), first-order hyperpolarizabilities (a.u.), and second-order hyperpolarizabilities (a.u.) of 2,2′-bithiophene rotamers^a.

	anti-gauche			syn-gauche
	HF	MP2	BH and HLYP	HF	MP2	BH and HLYP
𝜇	0.52	0.31	0.40	1.21	0.72	0.93
𝛼𝑥𝑥	178.53	184.76	186.63	177.29	183.13	184.95
𝛼𝑦𝑦	84.85	86.72	84.30	125.80	127.96	126.58
𝛼𝑧𝑧	127.99	129.81	128.68	86.73	88.65	86.27
⟨𝛼⟩	130.46	133.76	133.20	129.94	133.25	132.60
Δ𝛼	81.71	85.28	89.22	78.70	82.29	85.98
𝛽𝑥𝑥𝑦	2.7	−3.1	7.0	0.0	0.0	0.0
𝛽𝑦𝑦𝑦	29.9	30.3	32.2	0.0	0.0	0.0
𝛽𝑧𝑧𝑦	16.1	−3.3	7.0	0.0	0.0	0.0
𝛽𝑥𝑥𝑧	0.0	0.0	0.0	45.7	31.5	59.0
𝛽𝑦𝑦𝑧	0.0	0.0	0.0	22.5	−4.0	27.0
𝛽𝑧𝑧𝑧	0.0	0.0	0.0	40.8	16.3	21.9
𝛽𝜇	48.7	23.9	46.2	109.0	43.8	107.9
𝛾𝑥𝑥𝑥𝑥	102128			90352
𝛾𝑦𝑦𝑦𝑦	21824			22464
𝛾𝑧𝑧𝑧𝑧	21392			21216
𝛾𝑥𝑥𝑦𝑦	13312			12960
𝛾𝑥𝑥𝑧𝑧	6432			7744
𝛾𝑦𝑦𝑧𝑧	7536			6928
𝛾^b	39981			37859

aThe calculations were performed with the POL basis set on the MP2/6-311G** geometries.
^bThe HF/POL ⟨𝛾⟩ value of the thiophene monomer is calculated to be 14850 a.u..